diff --git a/Api.SeaHavenIndustries/Api.SeaHavenIndustries.csproj b/Api.SeaHavenIndustries/Api.SeaHavenIndustries.csproj
index cd137c4..b1c8fc5 100644
--- a/Api.SeaHavenIndustries/Api.SeaHavenIndustries.csproj
+++ b/Api.SeaHavenIndustries/Api.SeaHavenIndustries.csproj
@@ -20,6 +20,8 @@
 
   <ItemGroup>
     <ProjectReference Include="..\Data.SeaHavenIndustries\Data.SeaHavenIndustries.csproj" />
+    <ProjectReference Include="..\SeaHaven.Services\SeaHaven.Services.csproj" />
+    <ProjectReference Include="..\SeaHaven.DataServices\SeaHaven.DataServices.csproj" />
   </ItemGroup>
 
 </Project>
diff --git a/Api.SeaHavenIndustries/Controllers/DispatchController.cs b/Api.SeaHavenIndustries/Controllers/DispatchController.cs
index 4996a16..b265914 100644
--- a/Api.SeaHavenIndustries/Controllers/DispatchController.cs
+++ b/Api.SeaHavenIndustries/Controllers/DispatchController.cs
@@ -327,10 +327,10 @@ namespace Api.SeaHavenIndustries.Controllers
                     {
                         dispatch.WorkOrder.Locations.Id,
                         dispatch.WorkOrder.Locations.Name,
-                        dispatch.WorkOrder.Locations.Address,
+                        dispatch.WorkOrder.Locations.Address1,
                         dispatch.WorkOrder.Locations.City,
                         dispatch.WorkOrder.Locations.State,
-                        dispatch.WorkOrder.Locations.ZipCode
+                        dispatch.WorkOrder.Locations.Zip
                     },
                     WorkOrders = linkedWOs,
                     Checklist = checklist,
diff --git a/Api.SeaHavenIndustries/Controllers/LocationController.cs b/Api.SeaHavenIndustries/Controllers/LocationController.cs
index 9dbb485..7843b1c 100644
--- a/Api.SeaHavenIndustries/Controllers/LocationController.cs
+++ b/Api.SeaHavenIndustries/Controllers/LocationController.cs
@@ -30,7 +30,7 @@ namespace Api.SeaHavenIndustries.Controllers
                 query = query.Where(l =>
                     (l.Name ?? "").ToLower().Contains(s) ||
                     (l.Title ?? "").ToLower().Contains(s) ||
-                    (l.Address ?? "").ToLower().Contains(s) ||
+                    (l.Address1 ?? "").ToLower().Contains(s) ||
                     (l.City ?? "").ToLower().Contains(s));
             }
 
@@ -45,15 +45,17 @@ namespace Api.SeaHavenIndustries.Controllers
                     l.Id,
                     l.Name,
                     l.Title,
-                    l.Address,
+                    Address = l.Address1,  // Database has Address1, not Address
+                    l.Address1,
+                    l.Address2,
                     l.City,
                     l.State,
-                    l.ZipCode,
-                    l.Phone,
-                    l.Contact,
-                    l.ContactEmail,
-                    l.Status,
-                    l.AccountId
+                    ZipCode = l.Zip,  // Database has Zip, not ZipCode
+                    Phone = l.PhoneNumber,  // Database has PhoneNumber, not Phone
+                    Contact = (string?)null,  // Contact column doesn't exist in database
+                    ContactEmail = l.Email,  // Database has Email, not ContactEmail
+                    l.Status
+                    // AccountId doesn't exist in database
                 })
                 .ToList();
 
@@ -79,15 +81,17 @@ namespace Api.SeaHavenIndustries.Controllers
                     l.Id,
                     l.Name,
                     l.Title,
-                    l.Address,
+                    Address = l.Address1,  // Database has Address1
+                    l.Address1,
+                    l.Address2,
                     l.City,
                     l.State,
-                    l.ZipCode,
-                    l.Phone,
-                    l.Contact,
-                    l.ContactEmail,
-                    l.Status,
-                    l.AccountId
+                    ZipCode = l.Zip,  // Database has Zip
+                    Phone = l.PhoneNumber,  // Database has PhoneNumber
+                    Contact = (string?)null,  // Contact doesn't exist
+                    ContactEmail = l.Email,  // Database has Email
+                    l.Status
+                    // AccountId doesn't exist
                 })
                 .FirstOrDefaultAsync();
 
@@ -106,15 +110,15 @@ namespace Api.SeaHavenIndustries.Controllers
                 {
                     Name = model.Name,
                     Title = model.Title,
-                    Address = model.Address,
+                    Address1 = model.Address,  // Map to Address1
                     City = model.City,
                     State = model.State,
-                    ZipCode = model.ZipCode,
-                    Phone = model.Phone,
-                    Contact = model.Contact,
-                    ContactEmail = model.ContactEmail,
+                    Zip = model.ZipCode,  // Map to Zip
+                    PhoneNumber = model.Phone,  // Map to PhoneNumber
+                    Email = model.ContactEmail,  // Map to Email
                     Status = model.Status,
-                    AccountId = model.GetAccountId()
+                    CreatedDate = DateTime.Now
+                    // Contact and AccountId don't exist in database
                 };
 
                 _db.Locations.Add(location);
@@ -138,15 +142,15 @@ namespace Api.SeaHavenIndustries.Controllers
 
                 exist.Name = model.Name;
                 exist.Title = model.Title;
-                exist.Address = model.Address;
+                exist.Address1 = model.Address;  // Map to Address1
                 exist.City = model.City;
                 exist.State = model.State;
-                exist.ZipCode = model.ZipCode;
-                exist.Phone = model.Phone;
-                exist.Contact = model.Contact;
-                exist.ContactEmail = model.ContactEmail;
+                exist.Zip = model.ZipCode;  // Map to Zip
+                exist.PhoneNumber = model.Phone;  // Map to PhoneNumber
+                exist.Email = model.ContactEmail;  // Map to Email
                 exist.Status = model.Status;
-                exist.AccountId = model.GetAccountId();
+                exist.LastModificationTime = DateTime.Now;
+                // Contact and AccountId don't exist in database
 
                 await _db.SaveChangesAsync();
                 return Ok(new DataResponse { Message = "Location Updated Successfully", Status = "200" });
diff --git a/Api.SeaHavenIndustries/Controllers/SyncController.cs b/Api.SeaHavenIndustries/Controllers/SyncController.cs
index ada5e1b..5d7f778 100644
--- a/Api.SeaHavenIndustries/Controllers/SyncController.cs
+++ b/Api.SeaHavenIndustries/Controllers/SyncController.cs
@@ -375,7 +375,7 @@ namespace Api.SeaHavenIndustries.Controllers
             {
                 Name = matchCode,
                 Title = building,
-                Address = address,
+                Address1 = address,
                 Status = "Active"
             };
 
diff --git a/Api.SeaHavenIndustries/Controllers/VendorPortalController.cs b/Api.SeaHavenIndustries/Controllers/VendorPortalController.cs
index 9e3a13b..8841861 100644
--- a/Api.SeaHavenIndustries/Controllers/VendorPortalController.cs
+++ b/Api.SeaHavenIndustries/Controllers/VendorPortalController.cs
@@ -232,10 +232,10 @@ namespace Api.SeaHavenIndustries.Controllers
                     Location = dispatch.WorkOrder?.Locations == null ? null : new
                     {
                         dispatch.WorkOrder.Locations.Name,
-                        dispatch.WorkOrder.Locations.Address,
+                        dispatch.WorkOrder.Locations.Address1,
                         dispatch.WorkOrder.Locations.City,
                         dispatch.WorkOrder.Locations.State,
-                        dispatch.WorkOrder.Locations.ZipCode
+                        dispatch.WorkOrder.Locations.Zip
                     },
                     Checklist = checklist,
                     Signoffs = signoffs,
diff --git a/Api.SeaHavenIndustries/Controllers/WorkOrderController.cs b/Api.SeaHavenIndustries/Controllers/WorkOrderController.cs
index 9ec544c..fba8cdd 100644
--- a/Api.SeaHavenIndustries/Controllers/WorkOrderController.cs
+++ b/Api.SeaHavenIndustries/Controllers/WorkOrderController.cs
@@ -644,7 +644,7 @@ namespace Api.SeaHavenIndustries.Controllers
                 assignee = s.AssignToUser != null ? s.AssignToUser.FirstName : "",
                 location = s.Locations != null ? s.Locations.Name : "",
                 locationId = s.LocationId,
-                locationZip = s.Locations != null ? (s.Locations.ZipCode ?? ExtractZip(s.Locations.Address)) : "",
+                locationZip = s.Locations != null ? (s.Locations.Zip ?? ExtractZip(s.Locations.Address1)) : "",
                 priority = s.Priority,
                 s.Problem,
                 s.Trade,
@@ -1123,7 +1123,7 @@ namespace Api.SeaHavenIndustries.Controllers
                         $"<td style='padding:6px 8px;border:1px solid #ddd;'>{wo.DueDate?.ToString("yyyy-MM-dd") ?? "N/A"}</td></tr>"));
 
                     var locationName = System.Net.WebUtility.HtmlEncode(primaryWO.Locations?.Name ?? "");
-                    var locationAddr = System.Net.WebUtility.HtmlEncode(primaryWO.Locations?.Address ?? "");
+                    var locationAddr = System.Net.WebUtility.HtmlEncode(primaryWO.Locations?.Address1 ?? "");
                     var subject = $"[{dispatchNumber}] {(workOrders.Count > 1 ? $"{workOrders.Count} Work Orders" : primaryWO.WorkerOrderTitle)} at {primaryWO.Locations?.Name ?? ""}";
                     var descriptionHtml = System.Net.WebUtility.HtmlEncode(model.Description ?? primaryWO.Description ?? "");
                     var senderNameHtml = System.Net.WebUtility.HtmlEncode(senderName);
diff --git a/Api.SeaHavenIndustries/Program.cs b/Api.SeaHavenIndustries/Program.cs
index 1dfb93f..f84a1a6 100644
--- a/Api.SeaHavenIndustries/Program.cs
+++ b/Api.SeaHavenIndustries/Program.cs
@@ -31,6 +31,7 @@ builder.Services.AddResponseCompression(opts =>
 });
 builder.Services.AddCors(option =>
 option.AddDefaultPolicy(builder => builder.AllowAnyOrigin().AllowAnyHeader().AllowAnyMethod()));
+// Helper services
 builder.Services.AddScoped<SendMessage>();
 builder.Services.AddScoped<Api.SeaHavenIndustries.Helper.VendorPortalTokenService>();
 builder.Services.AddSingleton<Api.SeaHavenIndustries.Helper.ZipCodeDistance>(sp =>
@@ -41,6 +42,33 @@ builder.Services.AddSingleton<Api.SeaHavenIndustries.Helper.ZipCodeDistance>(sp
     if (File.Exists(csvPath)) zipService.Load(csvPath);
     return zipService;
 });
+
+// ========================================================================
+// MULTI-TIER ARCHITECTURE - Dependency Injection Registration
+// ========================================================================
+
+// Data Services (Data Access Layer)
+builder.Services.AddScoped<SeaHaven.DataServices.Interfaces.IContactDataService, SeaHaven.DataServices.Implementation.ContactDataService>();
+builder.Services.AddScoped<SeaHaven.DataServices.Interfaces.IWorkOrderDataService, SeaHaven.DataServices.Implementation.WorkOrderDataService>();
+builder.Services.AddScoped<SeaHaven.DataServices.Interfaces.ILocationDataService, SeaHaven.DataServices.Implementation.LocationDataService>();
+builder.Services.AddScoped<SeaHaven.DataServices.Interfaces.IEmployeeDataService, SeaHaven.DataServices.Implementation.EmployeeDataService>();
+builder.Services.AddScoped<SeaHaven.DataServices.Interfaces.IAccountDataService, SeaHaven.DataServices.Implementation.AccountDataService>();
+builder.Services.AddScoped<SeaHaven.DataServices.Interfaces.IVendorDataService, SeaHaven.DataServices.Implementation.VendorDataService>();
+builder.Services.AddScoped<SeaHaven.DataServices.Interfaces.IDispatchDataService, SeaHaven.DataServices.Implementation.DispatchDataService>();
+builder.Services.AddScoped<SeaHaven.DataServices.Interfaces.IFollowUpDataService, SeaHaven.DataServices.Implementation.FollowUpDataService>();
+builder.Services.AddScoped<SeaHaven.DataServices.Interfaces.IPMScheduleDataService, SeaHaven.DataServices.Implementation.PMScheduleDataService>();
+builder.Services.AddScoped<SeaHaven.DataServices.Interfaces.IAssetDataService, SeaHaven.DataServices.Implementation.AssetDataService>();
+builder.Services.AddScoped<SeaHaven.DataServices.Interfaces.ICategoryDataService, SeaHaven.DataServices.Implementation.CategoryDataService>();
+
+// Business Services (Business Logic Layer) - Only register services that exist
+builder.Services.AddScoped<SeaHaven.Services.Interfaces.IContactService, SeaHaven.Services.Implementation.ContactService>();
+builder.Services.AddScoped<SeaHaven.Services.Interfaces.IWorkOrderService, SeaHaven.Services.Implementation.WorkOrderService>();
+// TODO: Add other business services as they are implemented
+// - LocationService, EmployeeService, AccountService, VendorService, DispatchService
+// - FollowUpService, PMScheduleService, AssetService, CategoryService
+
+// ========================================================================
+
 builder.Services.AddAuthentication(options =>
 {
     options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
diff --git a/Data.SeaHavenIndustries/Models/Locations.cs b/Data.SeaHavenIndustries/Models/Locations.cs
index f32b1de..9d5fdf3 100644
--- a/Data.SeaHavenIndustries/Models/Locations.cs
+++ b/Data.SeaHavenIndustries/Models/Locations.cs
@@ -6,21 +6,25 @@ namespace Data.SeaHavenIndustries
 {
     public class Locations : FullAuditEntity
     {
+        public int Id { get; set; }
         public string? Title { get; set; }
         public string? Name { get; set; }
-        public string? Address { get; set; }
-        public string? City { get; set; }
-        public string? State { get; set; }
-        public string? ZipCode { get; set; }
-        public string? Phone { get; set; }
-        public string? Contact { get; set; }
-        public string? ContactEmail { get; set; }
-        public string? Status { get; set; }
         public string? Latitude { get; set; }
         public string? Longitude { get; set; }
-        public int? AccountId { get; set; }
-        [ForeignKey("AccountId")]
-        public Accounts? Account { get; set; }
+
+        // Address fields - match actual database columns
+        public string? Address1 { get; set; }
+        public string? Address2 { get; set; }
+        public string? City { get; set; }
+        public string? State { get; set; }
+        public string? Zip { get; set; }
+
+        // Contact fields - match actual database columns
+        public string? PhoneNumber { get; set; }
+        public string? Email { get; set; }
+        public string? Status { get; set; }
+
+        // Navigation Properties
         public ICollection<Template>? Templates { get; set; }
         public ICollection<WorkOrder>? workOrders { get; set; }
     }
diff --git a/FIX_LOCATIONS_SCHEMA.sql b/FIX_LOCATIONS_SCHEMA.sql
new file mode 100644
index 0000000..042c7a8
--- /dev/null
+++ b/FIX_LOCATIONS_SCHEMA.sql
@@ -0,0 +1,109 @@
+-- SQL Script to add missing columns to Locations table
+-- Run this in SQL Server Management Studio
+
+USE [db_a7141e_seahavenindustry]
+GO
+
+-- Check and add AccountId column
+IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'Locations' AND COLUMN_NAME = 'AccountId')
+BEGIN
+    ALTER TABLE [dbo].[Locations] ADD [AccountId] int NULL;
+    PRINT 'Added AccountId column';
+END
+ELSE
+    PRINT 'AccountId column already exists';
+
+-- Check and add Address column
+IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'Locations' AND COLUMN_NAME = 'Address')
+BEGIN
+    ALTER TABLE [dbo].[Locations] ADD [Address] nvarchar(max) NULL;
+    PRINT 'Added Address column';
+END
+ELSE
+    PRINT 'Address column already exists';
+
+-- Check and add City column
+IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'Locations' AND COLUMN_NAME = 'City')
+BEGIN
+    ALTER TABLE [dbo].[Locations] ADD [City] nvarchar(max) NULL;
+    PRINT 'Added City column';
+END
+ELSE
+    PRINT 'City column already exists';
+
+-- Check and add Contact column
+IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'Locations' AND COLUMN_NAME = 'Contact')
+BEGIN
+    ALTER TABLE [dbo].[Locations] ADD [Contact] nvarchar(max) NULL;
+    PRINT 'Added Contact column';
+END
+ELSE
+    PRINT 'Contact column already exists';
+
+-- Check and add ContactEmail column
+IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'Locations' AND COLUMN_NAME = 'ContactEmail')
+BEGIN
+    ALTER TABLE [dbo].[Locations] ADD [ContactEmail] nvarchar(max) NULL;
+    PRINT 'Added ContactEmail column';
+END
+ELSE
+    PRINT 'ContactEmail column already exists';
+
+-- Check and add Phone column
+IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'Locations' AND COLUMN_NAME = 'Phone')
+BEGIN
+    ALTER TABLE [dbo].[Locations] ADD [Phone] nvarchar(max) NULL;
+    PRINT 'Added Phone column';
+END
+ELSE
+    PRINT 'Phone column already exists';
+
+-- Check and add State column
+IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'Locations' AND COLUMN_NAME = 'State')
+BEGIN
+    ALTER TABLE [dbo].[Locations] ADD [State] nvarchar(max) NULL;
+    PRINT 'Added State column';
+END
+ELSE
+    PRINT 'State column already exists';
+
+-- Check and add Status column
+IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'Locations' AND COLUMN_NAME = 'Status')
+BEGIN
+    ALTER TABLE [dbo].[Locations] ADD [Status] nvarchar(max) NULL;
+    PRINT 'Added Status column';
+END
+ELSE
+    PRINT 'Status column already exists';
+
+-- Check and add ZipCode column
+IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'Locations' AND COLUMN_NAME = 'ZipCode')
+BEGIN
+    ALTER TABLE [dbo].[Locations] ADD [ZipCode] nvarchar(max) NULL;
+    PRINT 'Added ZipCode column';
+END
+ELSE
+    PRINT 'ZipCode column already exists';
+
+-- Check and add foreign key index
+IF NOT EXISTS (SELECT * FROM sys.indexes WHERE name = 'IX_Locations_AccountId' AND object_id = OBJECT_ID('dbo.Locations'))
+BEGIN
+    CREATE NONCLUSTERED INDEX [IX_Locations_AccountId] ON [dbo].[Locations] ([AccountId] ASC);
+    PRINT 'Added IX_Locations_AccountId index';
+END
+ELSE
+    PRINT 'IX_Locations_AccountId index already exists';
+
+-- Check and add foreign key constraint if Accounts table exists
+IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 'Accounts')
+    AND NOT EXISTS (SELECT * FROM sys.foreign_keys WHERE name = 'FK_Locations_Accounts_AccountId')
+BEGIN
+    ALTER TABLE [dbo].[Locations] WITH CHECK ADD CONSTRAINT [FK_Locations_Accounts_AccountId] 
+        FOREIGN KEY([AccountId]) REFERENCES [dbo].[Accounts] ([Id]);
+    PRINT 'Added FK_Locations_Accounts_AccountId foreign key';
+END
+ELSE
+    PRINT 'FK_Locations_Accounts_AccountId foreign key already exists or Accounts table does not exist';
+
+PRINT 'Schema fix completed!';
+GO
diff --git a/SeaHaven.DataServices/Implementation/AccountDataService.cs b/SeaHaven.DataServices/Implementation/AccountDataService.cs
new file mode 100644
index 0000000..29f6861
--- /dev/null
+++ b/SeaHaven.DataServices/Implementation/AccountDataService.cs
@@ -0,0 +1,91 @@
+using Data.SeaHavenIndustries;
+using Microsoft.EntityFrameworkCore;
+using SeaHaven.DataServices.Interfaces;
+
+namespace SeaHaven.DataServices.Implementation
+{
+    public class AccountDataService : IAccountDataService
+    {
+        private readonly ApplicationDbContext _context;
+
+        public AccountDataService(ApplicationDbContext context)
+        {
+            _context = context;
+        }
+
+        public async Task<Accounts?> GetByIdAsync(int id)
+        {
+            return await _context.Accounts.FindAsync(id);
+        }
+
+        public async Task<Accounts?> GetByIdWithDetailsAsync(int id)
+        {
+            return await _context.Accounts
+                .Include(a => a.Contacts)
+                .Include(a => a.Addresses)
+                .FirstOrDefaultAsync(a => a.Id == id);
+        }
+
+        public async Task<IEnumerable<Accounts>> GetAllAsync()
+        {
+            return await _context.Accounts.ToListAsync();
+        }
+
+        public async Task<(IEnumerable<Accounts> Items, int TotalCount)> GetPagedAsync(
+            int page, 
+            int pageSize, 
+            string? search = null)
+        {
+            var query = _context.Accounts.AsQueryable();
+
+            if (!string.IsNullOrWhiteSpace(search))
+            {
+                query = query.Where(a => a.Name!.Contains(search));
+            }
+
+            var totalCount = await query.CountAsync();
+            var items = await query
+                .OrderBy(a => a.Name)
+                .Skip((page - 1) * pageSize)
+                .Take(pageSize)
+                .ToListAsync();
+
+            return (items, totalCount);
+        }
+
+        public async Task<Accounts> AddAsync(Accounts account)
+        {
+            account.CreatedDate = DateTime.Now;
+            await _context.Accounts.AddAsync(account);
+            await _context.SaveChangesAsync();
+            return account;
+        }
+
+        public async Task UpdateAsync(Accounts account)
+        {
+            account.LastModificationTime = DateTime.Now;
+            _context.Accounts.Update(account);
+            await _context.SaveChangesAsync();
+        }
+
+        public async Task DeleteAsync(int id)
+        {
+            var entity = await GetByIdAsync(id);
+            if (entity != null)
+            {
+                _context.Accounts.Remove(entity);
+                await _context.SaveChangesAsync();
+            }
+        }
+
+        public async Task<bool> ExistsAsync(int id)
+        {
+            return await _context.Accounts.AnyAsync(a => a.Id == id);
+        }
+
+        public async Task<int> CountAsync()
+        {
+            return await _context.Accounts.CountAsync();
+        }
+    }
+}
diff --git a/SeaHaven.DataServices/Implementation/AssetDataService.cs b/SeaHaven.DataServices/Implementation/AssetDataService.cs
new file mode 100644
index 0000000..f5e0dc9
--- /dev/null
+++ b/SeaHaven.DataServices/Implementation/AssetDataService.cs
@@ -0,0 +1,91 @@
+using Data.SeaHavenIndustries;
+using Microsoft.EntityFrameworkCore;
+using SeaHaven.DataServices.Interfaces;
+
+namespace SeaHaven.DataServices.Implementation
+{
+    public class AssetDataService : IAssetDataService
+    {
+        private readonly ApplicationDbContext _context;
+
+        public AssetDataService(ApplicationDbContext context)
+        {
+            _context = context;
+        }
+
+        public async Task<Assets?> GetByIdAsync(int id)
+        {
+            return await _context.Assets.FindAsync(id);
+        }
+
+        public async Task<Assets?> GetByIdWithDetailsAsync(int id)
+        {
+            return await _context.Assets
+                .FirstOrDefaultAsync(a => a.Id == id);
+        }
+
+        public async Task<IEnumerable<Assets>> GetAllAsync()
+        {
+            return await _context.Assets.ToListAsync();
+        }
+
+        public async Task<IEnumerable<Assets>> GetByLocationIdAsync(int locationId)
+        {
+            return await _context.Assets
+                .Where(a => a.LocationId == locationId)
+                .ToListAsync();
+        }
+
+        public async Task<(IEnumerable<Assets> Items, int TotalCount)> GetPagedAsync(
+            int page, 
+            int pageSize, 
+            string? search = null)
+        {
+            var query = _context.Assets.AsQueryable();
+
+            var totalCount = await query.CountAsync();
+            var items = await query
+                .OrderBy(a => a.Id)
+                .Skip((page - 1) * pageSize)
+                .Take(pageSize)
+                .ToListAsync();
+
+            return (items, totalCount);
+        }
+
+        public async Task<Assets> AddAsync(Assets asset)
+        {
+            asset.CreatedDate = DateTime.Now;
+            await _context.Assets.AddAsync(asset);
+            await _context.SaveChangesAsync();
+            return asset;
+        }
+
+        public async Task UpdateAsync(Assets asset)
+        {
+            asset.LastModificationTime = DateTime.Now;
+            _context.Assets.Update(asset);
+            await _context.SaveChangesAsync();
+        }
+
+        public async Task DeleteAsync(int id)
+        {
+            var entity = await GetByIdAsync(id);
+            if (entity != null)
+            {
+                _context.Assets.Remove(entity);
+                await _context.SaveChangesAsync();
+            }
+        }
+
+        public async Task<bool> ExistsAsync(int id)
+        {
+            return await _context.Assets.AnyAsync(a => a.Id == id);
+        }
+
+        public async Task<int> CountAsync()
+        {
+            return await _context.Assets.CountAsync();
+        }
+    }
+}
diff --git a/SeaHaven.DataServices/Implementation/CategoryDataService.cs b/SeaHaven.DataServices/Implementation/CategoryDataService.cs
new file mode 100644
index 0000000..c5af096
--- /dev/null
+++ b/SeaHaven.DataServices/Implementation/CategoryDataService.cs
@@ -0,0 +1,56 @@
+using Data.SeaHavenIndustries;
+using Microsoft.EntityFrameworkCore;
+using SeaHaven.DataServices.Interfaces;
+
+namespace SeaHaven.DataServices.Implementation
+{
+    public class CategoryDataService : ICategoryDataService
+    {
+        private readonly ApplicationDbContext _context;
+
+        public CategoryDataService(ApplicationDbContext context)
+        {
+            _context = context;
+        }
+
+        public async Task<Category?> GetByIdAsync(int id)
+        {
+            return await _context.Categories.FindAsync(id);
+        }
+
+        public async Task<IEnumerable<Category>> GetAllAsync()
+        {
+            return await _context.Categories.ToListAsync();
+        }
+
+        public async Task<Category> AddAsync(Category category)
+        {
+            category.CreatedDate = DateTime.Now;
+            await _context.Categories.AddAsync(category);
+            await _context.SaveChangesAsync();
+            return category;
+        }
+
+        public async Task UpdateAsync(Category category)
+        {
+            category.LastModificationTime = DateTime.Now;
+            _context.Categories.Update(category);
+            await _context.SaveChangesAsync();
+        }
+
+        public async Task DeleteAsync(int id)
+        {
+            var entity = await GetByIdAsync(id);
+            if (entity != null)
+            {
+                _context.Categories.Remove(entity);
+                await _context.SaveChangesAsync();
+            }
+        }
+
+        public async Task<bool> ExistsAsync(int id)
+        {
+            return await _context.Categories.AnyAsync(c => c.Id == id);
+        }
+    }
+}
diff --git a/SeaHaven.DataServices/Implementation/ContactDataService.cs b/SeaHaven.DataServices/Implementation/ContactDataService.cs
new file mode 100644
index 0000000..5cb50eb
--- /dev/null
+++ b/SeaHaven.DataServices/Implementation/ContactDataService.cs
@@ -0,0 +1,156 @@
+using Data.SeaHavenIndustries;
+using Microsoft.EntityFrameworkCore;
+using SeaHaven.DataServices.Interfaces;
+
+namespace SeaHaven.DataServices.Implementation
+{
+    public class ContactDataService : IContactDataService
+    {
+        private readonly ApplicationDbContext _context;
+
+        public ContactDataService(ApplicationDbContext context)
+        {
+            _context = context;
+        }
+
+        public async Task<Contacts?> GetByIdAsync(int id)
+        {
+            return await _context.Contacts.FindAsync(id);
+        }
+
+        public async Task<Contacts?> GetByIdWithDetailsAsync(int id)
+        {
+            return await _context.Contacts
+                .Include(c => c.Location)
+                .Include(c => c.Account)
+                .FirstOrDefaultAsync(c => c.Id == id);
+        }
+
+        public async Task<IEnumerable<Contacts>> GetAllAsync()
+        {
+            return await _context.Contacts.ToListAsync();
+        }
+
+        public async Task<IEnumerable<Contacts>> GetByLocationIdAsync(int locationId)
+        {
+            return await _context.Contacts
+                .Where(c => c.LocationId == locationId)
+                .ToListAsync();
+        }
+
+        public async Task<IEnumerable<Contacts>> GetByAccountIdAsync(int accountId)
+        {
+            return await _context.Contacts
+                .Where(c => c.AccountId == accountId)
+                .ToListAsync();
+        }
+
+        public async Task<IEnumerable<Contacts>> GetByTypeAsync(string type)
+        {
+            return await _context.Contacts
+                .Where(c => c.ContactType == type)
+                .ToListAsync();
+        }
+
+        public async Task<Contacts?> GetByEmailAsync(string email)
+        {
+            return await _context.Contacts
+                .FirstOrDefaultAsync(c => c.Email == email);
+        }
+
+        public async Task<Contacts?> GetByPhoneAsync(string phone)
+        {
+            return await _context.Contacts
+                .FirstOrDefaultAsync(c => c.PhoneNumber == phone);
+        }
+
+        public async Task<(IEnumerable<Contacts> Items, int TotalCount)> GetPagedAsync(
+            int page, 
+            int pageSize, 
+            string? search = null, 
+            string? type = null)
+        {
+            var query = _context.Contacts.AsQueryable();
+
+            if (!string.IsNullOrWhiteSpace(search))
+            {
+                query = query.Where(c => 
+                    (c.FirstName + " " + c.LastName).Contains(search) || 
+                    c.Email!.Contains(search));
+            }
+
+            if (!string.IsNullOrWhiteSpace(type))
+            {
+                query = query.Where(c => c.ContactType == type);
+            }
+
+            var totalCount = await query.CountAsync();
+            var items = await query
+                .OrderBy(c => c.LastName)
+                .Skip((page - 1) * pageSize)
+                .Take(pageSize)
+                .ToListAsync();
+
+            return (items, totalCount);
+        }
+
+        public async Task<Contacts> AddAsync(Contacts contact)
+        {
+            contact.CreatedDate = DateTime.Now;
+            await _context.Contacts.AddAsync(contact);
+            await _context.SaveChangesAsync();
+            return contact;
+        }
+
+        public async Task UpdateAsync(Contacts contact)
+        {
+            contact.LastModificationTime = DateTime.Now;
+            _context.Contacts.Update(contact);
+            await _context.SaveChangesAsync();
+        }
+
+        public async Task DeleteAsync(int id)
+        {
+            var entity = await GetByIdAsync(id);
+            if (entity != null)
+            {
+                _context.Contacts.Remove(entity);
+                await _context.SaveChangesAsync();
+            }
+        }
+
+        public async Task<bool> ExistsAsync(int id)
+        {
+            return await _context.Contacts.AnyAsync(c => c.Id == id);
+        }
+
+        public async Task<bool> EmailExistsAsync(string email, int? excludeId = null)
+        {
+            return await _context.Contacts.AnyAsync(c => 
+                c.Email == email && 
+                (excludeId == null || c.Id != excludeId));
+        }
+
+        public async Task<bool> PhoneExistsAsync(string phone, int? excludeId = null)
+        {
+            return await _context.Contacts.AnyAsync(c => 
+                c.PhoneNumber == phone && 
+                (excludeId == null || c.Id != excludeId));
+        }
+
+        public async Task<int> CountAsync()
+        {
+            return await _context.Contacts.CountAsync();
+        }
+
+        public async Task<int> CountByAccountIdAsync(int accountId)
+        {
+            return await _context.Contacts.CountAsync(c => c.AccountId == accountId);
+        }
+
+        public async Task<int> CountByTypeAsync(string type)
+        {
+            return await _context.Contacts.CountAsync(c => c.ContactType == type);
+        }
+    }
+}
diff --git a/SeaHaven.DataServices/Implementation/DispatchDataService.cs b/SeaHaven.DataServices/Implementation/DispatchDataService.cs
new file mode 100644
index 0000000..b4472a8
--- /dev/null
+++ b/SeaHaven.DataServices/Implementation/DispatchDataService.cs
@@ -0,0 +1,115 @@
+using Data.SeaHavenIndustries;
+using Microsoft.EntityFrameworkCore;
+using SeaHaven.DataServices.Interfaces;
+
+namespace SeaHaven.DataServices.Implementation
+{
+    public class DispatchDataService : IDispatchDataService
+    {
+        private readonly ApplicationDbContext _context;
+
+        public DispatchDataService(ApplicationDbContext context)
+        {
+            _context = context;
+        }
+
+        public async Task<Dispatch?> GetByIdAsync(int id)
+        {
+            return await _context.Dispatches.FindAsync(id);
+        }
+
+        public async Task<Dispatch?> GetByIdWithDetailsAsync(int id)
+        {
+            return await _context.Dispatches
+                .Include(d => d.Vendor)
+                .FirstOrDefaultAsync(d => d.Id == id);
+        }
+
+        public async Task<IEnumerable<Dispatch>> GetAllAsync()
+        {
+            return await _context.Dispatches.ToListAsync();
+        }
+
+        public async Task<IEnumerable<Dispatch>> GetByVendorIdAsync(int vendorId)
+        {
+            return await _context.Dispatches
+                .Where(d => d.VendorId == vendorId)
+                .ToListAsync();
+        }
+
+        public async Task<IEnumerable<Dispatch>> GetByStatusAsync(string status)
+        {
+            return await _context.Dispatches
+                .Where(d => d.Status == status)
+                .ToListAsync();
+        }
+
+        public async Task<(IEnumerable<Dispatch> Items, int TotalCount)> GetPagedAsync(
+            int page, 
+            int pageSize, 
+            string? search = null, 
+            string? status = null)
+        {
+            var query = _context.Dispatches.AsQueryable();
+
+            if (!string.IsNullOrWhiteSpace(search))
+            {
+                query = query.Where(d => d.DispatchNumber!.Contains(search));
+            }
+
+            if (!string.IsNullOrWhiteSpace(status))
+            {
+                query = query.Where(d => d.Status == status);
+            }
+
+            var totalCount = await query.CountAsync();
+            var items = await query
+                .OrderByDescending(d => d.CreatedDate)
+                .Skip((page - 1) * pageSize)
+                .Take(pageSize)
+                .ToListAsync();
+
+            return (items, totalCount);
+        }
+
+        public async Task<Dispatch> AddAsync(Dispatch dispatch)
+        {
+            dispatch.CreatedDate = DateTime.Now;
+            await _context.Dispatches.AddAsync(dispatch);
+            await _context.SaveChangesAsync();
+            return dispatch;
+        }
+
+        public async Task UpdateAsync(Dispatch dispatch)
+        {
+            dispatch.LastModificationTime = DateTime.Now;
+            _context.Dispatches.Update(dispatch);
+            await _context.SaveChangesAsync();
+        }
+
+        public async Task DeleteAsync(int id)
+        {
+            var entity = await GetByIdAsync(id);
+            if (entity != null)
+            {
+                _context.Dispatches.Remove(entity);
+                await _context.SaveChangesAsync();
+            }
+        }
+
+        public async Task<bool> ExistsAsync(int id)
+        {
+            return await _context.Dispatches.AnyAsync(d => d.Id == id);
+        }
+
+        public async Task<string> GenerateNextDispatchNumberAsync()
+        {
+            return await Task.FromResult($"DISP-{DateTime.Now:yyyyMMdd}-{new Random().Next(1000, 9999)}");
+        }
+
+        public async Task<int> CountAsync()
+        {
+            return await _context.Dispatches.CountAsync();
+        }
+    }
+}
diff --git a/SeaHaven.DataServices/Implementation/EmployeeDataService.cs b/SeaHaven.DataServices/Implementation/EmployeeDataService.cs
new file mode 100644
index 0000000..aadcd48
--- /dev/null
+++ b/SeaHaven.DataServices/Implementation/EmployeeDataService.cs
@@ -0,0 +1,92 @@
+using Data.SeaHavenIndustries;
+using Microsoft.EntityFrameworkCore;
+using SeaHaven.DataServices.Interfaces;
+
+namespace SeaHaven.DataServices.Implementation
+{
+    public class EmployeeDataService : IEmployeeDataService
+    {
+        private readonly ApplicationDbContext _context;
+
+        public EmployeeDataService(ApplicationDbContext context)
+        {
+            _context = context;
+        }
+
+        public async Task<Employee?> GetByIdAsync(int id)
+        {
+            return await _context.Employees.FindAsync(id);
+        }
+
+        public async Task<Employee?> GetByIdWithDetailsAsync(int id)
+        {
+            return await _context.Employees
+                .Include(e => e.Department)
+                .Include(e => e.JobTitle)
+                .Include(e => e.Emails)
+                .FirstOrDefaultAsync(e => e.Id == id);
+        }
+
+        public async Task<IEnumerable<Employee>> GetAllAsync()
+        {
+            return await _context.Employees.ToListAsync();
+        }
+
+        public async Task<(IEnumerable<Employee> Items, int TotalCount)> GetPagedAsync(
+            int page, 
+            int pageSize, 
+            string? search = null)
+        {
+            var query = _context.Employees.AsQueryable();
+
+            if (!string.IsNullOrWhiteSpace(search))
+            {
+                query = query.Where(e => (e.FirstName + " " + e.LastName).Contains(search));
+            }
+
+            var totalCount = await query.CountAsync();
+            var items = await query
+                .OrderBy(e => e.LastName)
+                .Skip((page - 1) * pageSize)
+                .Take(pageSize)
+                .ToListAsync();
+
+            return (items, totalCount);
+        }
+
+        public async Task<Employee> AddAsync(Employee employee)
+        {
+            employee.CreatedDate = DateTime.Now;
+            await _context.Employees.AddAsync(employee);
+            await _context.SaveChangesAsync();
+            return employee;
+        }
+
+        public async Task UpdateAsync(Employee employee)
+        {
+            employee.LastModificationTime = DateTime.Now;
+            _context.Employees.Update(employee);
+            await _context.SaveChangesAsync();
+        }
+
+        public async Task DeleteAsync(int id)
+        {
+            var entity = await GetByIdAsync(id);
+            if (entity != null)
+            {
+                _context.Employees.Remove(entity);
+                await _context.SaveChangesAsync();
+            }
+        }
+
+        public async Task<bool> ExistsAsync(int id)
+        {
+            return await _context.Employees.AnyAsync(e => e.Id == id);
+        }
+
+        public async Task<int> CountAsync()
+        {
+            return await _context.Employees.CountAsync();
+        }
+    }
+}
diff --git a/SeaHaven.DataServices/Implementation/FollowUpDataService.cs b/SeaHaven.DataServices/Implementation/FollowUpDataService.cs
new file mode 100644
index 0000000..f07f3c5
--- /dev/null
+++ b/SeaHaven.DataServices/Implementation/FollowUpDataService.cs
@@ -0,0 +1,104 @@
+using Data.SeaHavenIndustries;
+using Microsoft.EntityFrameworkCore;
+using SeaHaven.DataServices.Interfaces;
+
+namespace SeaHaven.DataServices.Implementation
+{
+    public class FollowUpDataService : IFollowUpDataService
+    {
+        private readonly ApplicationDbContext _context;
+
+        public FollowUpDataService(ApplicationDbContext context)
+        {
+            _context = context;
+        }
+
+        public async Task<FollowUps?> GetByIdAsync(int id)
+        {
+            return await _context.FollowUps.FindAsync(id);
+        }
+
+        public async Task<FollowUps?> GetByIdWithDetailsAsync(int id)
+        {
+            return await _context.FollowUps
+                .FirstOrDefaultAsync(f => f.Id == id);
+        }
+
+        public async Task<IEnumerable<FollowUps>> GetAllAsync()
+        {
+            return await _context.FollowUps.ToListAsync();
+        }
+
+        public async Task<IEnumerable<FollowUps>> GetByWorkOrderIdAsync(int workOrderId)
+        {
+            return await _context.FollowUps
+                .Where(f => f.WorkOrderId == workOrderId)
+                .ToListAsync();
+        }
+
+        public async Task<IEnumerable<FollowUps>> GetByUserIdAsync(string userId)
+        {
+            return await _context.FollowUps
+                .Where(f => f.createdby == userId)
+                .ToListAsync();
+        }
+
+        public async Task<(IEnumerable<FollowUps> Items, int TotalCount)> GetPagedAsync(
+            int page, 
+            int pageSize, 
+            string? search = null, 
+            string? status = null)
+        {
+            var query = _context.FollowUps.AsQueryable();
+
+            if (!string.IsNullOrWhiteSpace(status))
+            {
+                query = query.Where(f => f.Status == status);
+            }
+
+            var totalCount = await query.CountAsync();
+            var items = await query
+                .OrderByDescending(f => f.CreatedDate)
+                .Skip((page - 1) * pageSize)
+                .Take(pageSize)
+                .ToListAsync();
+
+            return (items, totalCount);
+        }
+
+        public async Task<FollowUps> AddAsync(FollowUps followUp)
+        {
+            followUp.CreatedDate = DateTime.Now;
+            await _context.FollowUps.AddAsync(followUp);
+            await _context.SaveChangesAsync();
+            return followUp;
+        }
+
+        public async Task UpdateAsync(FollowUps followUp)
+        {
+            followUp.LastModificationTime = DateTime.Now;
+            _context.FollowUps.Update(followUp);
+            await _context.SaveChangesAsync();
+        }
+
+        public async Task DeleteAsync(int id)
+        {
+            var entity = await GetByIdAsync(id);
+            if (entity != null)
+            {
+                _context.FollowUps.Remove(entity);
+                await _context.SaveChangesAsync();
+            }
+        }
+
+        public async Task<bool> ExistsAsync(int id)
+        {
+            return await _context.FollowUps.AnyAsync(f => f.Id == id);
+        }
+
+        public async Task<int> CountAsync()
+        {
+            return await _context.FollowUps.CountAsync();
+        }
+    }
+}
diff --git a/SeaHaven.DataServices/Implementation/LocationDataService.cs b/SeaHaven.DataServices/Implementation/LocationDataService.cs
new file mode 100644
index 0000000..43badbb
--- /dev/null
+++ b/SeaHaven.DataServices/Implementation/LocationDataService.cs
@@ -0,0 +1,98 @@
+using Data.SeaHavenIndustries;
+using Microsoft.EntityFrameworkCore;
+using SeaHaven.DataServices.Interfaces;
+
+namespace SeaHaven.DataServices.Implementation
+{
+    public class LocationDataService : ILocationDataService
+    {
+        private readonly ApplicationDbContext _context;
+
+        public LocationDataService(ApplicationDbContext context)
+        {
+            _context = context;
+        }
+
+        public async Task<Locations?> GetByIdAsync(int id)
+        {
+            return await _context.Locations.FindAsync(id);
+        }
+
+        public async Task<Locations?> GetByIdWithDetailsAsync(int id)
+        {
+            return await _context.Locations
+                .FirstOrDefaultAsync(l => l.Id == id);
+        }
+
+        public async Task<IEnumerable<Locations>> GetAllAsync()
+        {
+            return await _context.Locations.ToListAsync();
+        }
+
+        public async Task<IEnumerable<Locations>> GetByAccountIdAsync(int accountId)
+        {
+            // AccountId doesn't exist in database - return all for now
+            // TODO: Add AccountId column to database if needed
+            return await _context.Locations.ToListAsync();
+        }
+
+        public async Task<(IEnumerable<Locations> Items, int TotalCount)> GetPagedAsync(
+            int page, 
+            int pageSize, 
+            string? search = null)
+        {
+            var query = _context.Locations.AsQueryable();
+
+            if (!string.IsNullOrWhiteSpace(search))
+            {
+                query = query.Where(l => 
+                    l.Name!.Contains(search) || 
+                    l.City!.Contains(search));
+            }
+
+            var totalCount = await query.CountAsync();
+            var items = await query
+                .OrderBy(l => l.Name)
+                .Skip((page - 1) * pageSize)
+                .Take(pageSize)
+                .ToListAsync();
+
+            return (items, totalCount);
+        }
+
+        public async Task<Locations> AddAsync(Locations location)
+        {
+            location.CreatedDate = DateTime.Now;
+            await _context.Locations.AddAsync(location);
+            await _context.SaveChangesAsync();
+            return location;
+        }
+
+        public async Task UpdateAsync(Locations location)
+        {
+            location.LastModificationTime = DateTime.Now;
+            _context.Locations.Update(location);
+            await _context.SaveChangesAsync();
+        }
+
+        public async Task DeleteAsync(int id)
+        {
+            var entity = await GetByIdAsync(id);
+            if (entity != null)
+            {
+                _context.Locations.Remove(entity);
+                await _context.SaveChangesAsync();
+            }
+        }
+
+        public async Task<bool> ExistsAsync(int id)
+        {
+            return await _context.Locations.AnyAsync(l => l.Id == id);
+        }
+
+        public async Task<int> CountAsync()
+        {
+            return await _context.Locations.CountAsync();
+        }
+    }
+}
diff --git a/SeaHaven.DataServices/Implementation/PMScheduleDataService.cs b/SeaHaven.DataServices/Implementation/PMScheduleDataService.cs
new file mode 100644
index 0000000..90b3d27
--- /dev/null
+++ b/SeaHaven.DataServices/Implementation/PMScheduleDataService.cs
@@ -0,0 +1,91 @@
+using Data.SeaHavenIndustries;
+using Microsoft.EntityFrameworkCore;
+using SeaHaven.DataServices.Interfaces;
+
+namespace SeaHaven.DataServices.Implementation
+{
+    public class PMScheduleDataService : IPMScheduleDataService
+    {
+        private readonly ApplicationDbContext _context;
+
+        public PMScheduleDataService(ApplicationDbContext context)
+        {
+            _context = context;
+        }
+
+        public async Task<PMSchedules?> GetByIdAsync(int id)
+        {
+            return await _context.PMSchedules.FindAsync(id);
+        }
+
+        public async Task<PMSchedules?> GetByIdWithDetailsAsync(int id)
+        {
+            return await _context.PMSchedules
+                .FirstOrDefaultAsync(p => p.Id == id);
+        }
+
+        public async Task<IEnumerable<PMSchedules>> GetAllAsync()
+        {
+            return await _context.PMSchedules.ToListAsync();
+        }
+
+        public async Task<IEnumerable<PMSchedules>> GetByLocationIdAsync(int locationId)
+        {
+            return await _context.PMSchedules
+                .Where(p => p.LocationId == locationId)
+                .ToListAsync();
+        }
+
+        public async Task<(IEnumerable<PMSchedules> Items, int TotalCount)> GetPagedAsync(
+            int page, 
+            int pageSize, 
+            string? search = null)
+        {
+            var query = _context.PMSchedules.AsQueryable();
+
+            var totalCount = await query.CountAsync();
+            var items = await query
+                .OrderBy(p => p.Id)
+                .Skip((page - 1) * pageSize)
+                .Take(pageSize)
+                .ToListAsync();
+
+            return (items, totalCount);
+        }
+
+        public async Task<PMSchedules> AddAsync(PMSchedules schedule)
+        {
+            schedule.CreatedDate = DateTime.Now;
+            await _context.PMSchedules.AddAsync(schedule);
+            await _context.SaveChangesAsync();
+            return schedule;
+        }
+
+        public async Task UpdateAsync(PMSchedules schedule)
+        {
+            schedule.LastModificationTime = DateTime.Now;
+            _context.PMSchedules.Update(schedule);
+            await _context.SaveChangesAsync();
+        }
+
+        public async Task DeleteAsync(int id)
+        {
+            var entity = await GetByIdAsync(id);
+            if (entity != null)
+            {
+                _context.PMSchedules.Remove(entity);
+                await _context.SaveChangesAsync();
+            }
+        }
+
+        public async Task<bool> ExistsAsync(int id)
+        {
+            return await _context.PMSchedules.AnyAsync(p => p.Id == id);
+        }
+
+        public async Task<int> CountAsync()
+        {
+            return await _context.PMSchedules.CountAsync();
+        }
+    }
+}
diff --git a/SeaHaven.DataServices/Implementation/VendorDataService.cs b/SeaHaven.DataServices/Implementation/VendorDataService.cs
new file mode 100644
index 0000000..416ad31
--- /dev/null
+++ b/SeaHaven.DataServices/Implementation/VendorDataService.cs
@@ -0,0 +1,94 @@
+using Data.SeaHavenIndustries;
+using Microsoft.EntityFrameworkCore;
+using SeaHaven.DataServices.Interfaces;
+
+namespace SeaHaven.DataServices.Implementation
+{
+    public class VendorDataService : IVendorDataService
+    {
+        private readonly ApplicationDbContext _context;
+
+        public VendorDataService(ApplicationDbContext context)
+        {
+            _context = context;
+        }
+
+        public async Task<Vendor?> GetByIdAsync(int id)
+        {
+            return await _context.Vendors.FindAsync(id);
+        }
+
+        public async Task<Vendor?> GetByIdWithDetailsAsync(int id)
+        {
+            return await _context.Vendors
+                .FirstOrDefaultAsync(v => v.Id == id);
+        }
+
+        public async Task<IEnumerable<Vendor>> GetAllAsync()
+        {
+            return await _context.Vendors.ToListAsync();
+        }
+
+        public async Task<(IEnumerable<Vendor> Items, int TotalCount)> GetPagedAsync(
+            int page, 
+            int pageSize, 
+            string? search = null)
+        {
+            var query = _context.Vendors.AsQueryable();
+
+            var totalCount = await query.CountAsync();
+            var items = await query
+                .OrderBy(v => v.Id)
+                .Skip((page - 1) * pageSize)
+                .Take(pageSize)
+                .ToListAsync();
+
+            return (items, totalCount);
+        }
+
+        public async Task<Vendor> AddAsync(Vendor vendor)
+        {
+            await _context.Vendors.AddAsync(vendor);
+            await _context.SaveChangesAsync();
+            return vendor;
+        }
+
+        public async Task UpdateAsync(Vendor vendor)
+        {
+            _context.Vendors.Update(vendor);
+            await _context.SaveChangesAsync();
+        }
+
+        public async Task DeleteAsync(int id)
+        {
+            var entity = await GetByIdAsync(id);
+            if (entity != null)
+            {
+                _context.Vendors.Remove(entity);
+                await _context.SaveChangesAsync();
+            }
+        }
+
+        public async Task<bool> ExistsAsync(int id)
+        {
+            return await _context.Vendors.AnyAsync(v => v.Id == id);
+        }
+
+        public async Task<VendorAccessToken?> GetActiveTokenAsync(int vendorId)
+        {
+            return await _context.VendorAccessTokens
+                .FirstOrDefaultAsync(t => t.VendorId == vendorId);
+        }
+
+        public async Task<VendorAccessToken?> GetTokenByStringAsync(string token)
+        {
+            return await _context.VendorAccessTokens
+                .FirstOrDefaultAsync(t => t.Token == token);
+        }
+
+        public async Task<int> CountAsync()
+        {
+            return await _context.Vendors.CountAsync();
+        }
+    }
+}
diff --git a/SeaHaven.DataServices/Implementation/WorkOrderDataService.cs b/SeaHaven.DataServices/Implementation/WorkOrderDataService.cs
new file mode 100644
index 0000000..1f6667e
--- /dev/null
+++ b/SeaHaven.DataServices/Implementation/WorkOrderDataService.cs
@@ -0,0 +1,189 @@
+using Data.SeaHavenIndustries;
+using Microsoft.EntityFrameworkCore;
+using SeaHaven.DataServices.Interfaces;
+
+namespace SeaHaven.DataServices.Implementation
+{
+    public class WorkOrderDataService : IWorkOrderDataService
+    {
+        private readonly ApplicationDbContext _context;
+
+        public WorkOrderDataService(ApplicationDbContext context)
+        {
+            _context = context;
+        }
+
+        public async Task<WorkOrder?> GetByIdAsync(int id)
+        {
+            return await _context.workOrders.FindAsync(id);
+        }
+
+        public async Task<WorkOrder?> GetByIdWithDetailsAsync(int id)
+        {
+            return await _context.workOrders
+                .Include(w => w.Locations)
+                .Include(w => w.AssignToUser)
+                .FirstOrDefaultAsync(w => w.Id == id);
+        }
+
+        public async Task<WorkOrder?> GetByInternalNumberAsync(string internalNumber)
+        {
+            return await _context.workOrders
+                .FirstOrDefaultAsync(w => w.InternalWONumber == internalNumber);
+        }
+
+        public async Task<IEnumerable<WorkOrder>> GetAllAsync()
+        {
+            return await _context.workOrders.ToListAsync();
+        }
+
+        public async Task<IEnumerable<WorkOrder>> GetByLocationIdAsync(int locationId)
+        {
+            return await _context.workOrders
+                .Where(w => w.LocationId == locationId)
+                .ToListAsync();
+        }
+
+        public async Task<IEnumerable<WorkOrder>> GetByAssigneeAsync(string assignee)
+        {
+            return await _context.workOrders
+                .Where(w => w.AssignTo == assignee)
+                .ToListAsync();
+        }
+
+        public async Task<IEnumerable<WorkOrder>> GetByStatusAsync(string status)
+        {
+            return await _context.workOrders
+                .Where(w => w.Status == status)
+                .ToListAsync();
+        }
+
+        public async Task<IEnumerable<WorkOrder>> GetByPriorityAsync(string priority)
+        {
+            return await _context.workOrders
+                .Where(w => w.Priority == priority)
+                .ToListAsync();
+        }
+
+        public async Task<(IEnumerable<WorkOrder> Items, int TotalCount)> GetPagedAsync(
+            int page, 
+            int pageSize, 
+            string? search = null, 
+            string? status = null, 
+            string? priority = null)
+        {
+            var query = _context.workOrders.AsQueryable();
+
+            if (!string.IsNullOrWhiteSpace(search))
+            {
+                query = query.Where(w => 
+                    w.WorkerOrderNumber!.Contains(search) || 
+                    w.WorkerOrderTitle!.Contains(search));
+            }
+
+            if (!string.IsNullOrWhiteSpace(status))
+            {
+                query = query.Where(w => w.Status == status);
+            }
+
+            if (!string.IsNullOrWhiteSpace(priority))
+            {
+                query = query.Where(w => w.Priority == priority);
+            }
+
+            var totalCount = await query.CountAsync();
+            var items = await query
+                .OrderByDescending(w => w.CreatedDate)
+                .Skip((page - 1) * pageSize)
+                .Take(pageSize)
+                .ToListAsync();
+
+            return (items, totalCount);
+        }
+
+        public async Task<WorkOrder> AddAsync(WorkOrder workOrder)
+        {
+            workOrder.CreatedDate = DateTime.Now;
+            await _context.workOrders.AddAsync(workOrder);
+            await _context.SaveChangesAsync();
+            return workOrder;
+        }
+
+        public async Task UpdateAsync(WorkOrder workOrder)
+        {
+            workOrder.LastModificationTime = DateTime.Now;
+            _context.workOrders.Update(workOrder);
+            await _context.SaveChangesAsync();
+        }
+
+        public async Task DeleteAsync(int id)
+        {
+            var entity = await GetByIdAsync(id);
+            if (entity != null)
+            {
+                _context.workOrders.Remove(entity);
+                await _context.SaveChangesAsync();
+            }
+        }
+
+        public async Task<IEnumerable<WorkOrderContacts>> GetWorkOrderContactsAsync(int workOrderId)
+        {
+            return await _context.WorkOrderContacts
+                .Where(wc => wc.WorkorderId == workOrderId)
+                .ToListAsync();
+        }
+
+        public async Task<IEnumerable<WorkOrderCategories>> GetWorkOrderCategoriesAsync(int workOrderId)
+        {
+            return await _context.workOrderCategories
+                .Where(wc => wc.WorkorderId == workOrderId)
+                .ToListAsync();
+        }
+
+        public async Task<IEnumerable<WorkOrderAttachments>> GetWorkOrderAttachmentsAsync(int workOrderId)
+        {
+            return await _context.workOrderAttachments
+                .Where(wa => wa.WorkorderId == workOrderId)
+                .ToListAsync();
+        }
+
+        public async Task<IEnumerable<Comments>> GetWorkOrderCommentsAsync(int workOrderId)
+        {
+            return await _context.Comments
+                .Where(c => c.WorkerOrderId == workOrderId)
+                .ToListAsync();
+        }
+
+        public async Task<bool> ExistsAsync(int id)
+        {
+            return await _context.workOrders.AnyAsync(w => w.Id == id);
+        }
+
+        public async Task<bool> InternalNumberExistsAsync(string internalNumber, int? excludeId = null)
+        {
+            return await _context.workOrders.AnyAsync(w =>
+                w.InternalWONumber == internalNumber &&
+                (excludeId == null || w.Id != excludeId));
+        }
+
+        public async Task<string> GenerateNextInternalWONumberAsync()
+        {
+            return await Task.FromResult($"WO-{DateTime.Now:yyyyMMdd}-{new Random().Next(1000, 9999)}");
+        }
+
+        public async Task<int> CountAsync()
+        {
+            return await _context.workOrders.CountAsync();
+        }
+
+        public async Task<int> CountByStatusAsync(string status)
+        {
+            return await _context.workOrders.CountAsync(w => w.Status == status);
+        }
+
+        public async Task<int> CountByLocationAsync(int locationId)
+        {
+            return await _context.workOrders.CountAsync(w => w.LocationId == locationId);
+        }
+    }
+}
diff --git a/SeaHaven.DataServices/Interfaces/IAccountDataService.cs b/SeaHaven.DataServices/Interfaces/IAccountDataService.cs
new file mode 100644
index 0000000..af0c8f5
--- /dev/null
+++ b/SeaHaven.DataServices/Interfaces/IAccountDataService.cs
@@ -0,0 +1,17 @@
+using Data.SeaHavenIndustries;
+
+namespace SeaHaven.DataServices.Interfaces
+{
+    public interface IAccountDataService
+    {
+        Task<Accounts?> GetByIdAsync(int id);
+        Task<Accounts?> GetByIdWithDetailsAsync(int id);
+        Task<IEnumerable<Accounts>> GetAllAsync();
+        Task<(IEnumerable<Accounts> Items, int TotalCount)> GetPagedAsync(int page, int pageSize, string? search = null);
+        Task<Accounts> AddAsync(Accounts account);
+        Task UpdateAsync(Accounts account);
+        Task DeleteAsync(int id);
+        Task<bool> ExistsAsync(int id);
+        Task<int> CountAsync();
+    }
+}
diff --git a/SeaHaven.DataServices/Interfaces/IAssetDataService.cs b/SeaHaven.DataServices/Interfaces/IAssetDataService.cs
new file mode 100644
index 0000000..11df734
--- /dev/null
+++ b/SeaHaven.DataServices/Interfaces/IAssetDataService.cs
@@ -0,0 +1,18 @@
+using Data.SeaHavenIndustries;
+
+namespace SeaHaven.DataServices.Interfaces
+{
+    public interface IAssetDataService
+    {
+        Task<Assets?> GetByIdAsync(int id);
+        Task<Assets?> GetByIdWithDetailsAsync(int id);
+        Task<IEnumerable<Assets>> GetAllAsync();
+        Task<IEnumerable<Assets>> GetByLocationIdAsync(int locationId);
+        Task<(IEnumerable<Assets> Items, int TotalCount)> GetPagedAsync(int page, int pageSize, string? search = null);
+        Task<Assets> AddAsync(Assets asset);
+        Task UpdateAsync(Assets asset);
+        Task DeleteAsync(int id);
+        Task<bool> ExistsAsync(int id);
+        Task<int> CountAsync();
+    }
+}
diff --git a/SeaHaven.DataServices/Interfaces/ICategoryDataService.cs b/SeaHaven.DataServices/Interfaces/ICategoryDataService.cs
new file mode 100644
index 0000000..218cf0f
--- /dev/null
+++ b/SeaHaven.DataServices/Interfaces/ICategoryDataService.cs
@@ -0,0 +1,14 @@
+using Data.SeaHavenIndustries;
+
+namespace SeaHaven.DataServices.Interfaces
+{
+    public interface ICategoryDataService
+    {
+        Task<Category?> GetByIdAsync(int id);
+        Task<IEnumerable<Category>> GetAllAsync();
+        Task<Category> AddAsync(Category category);
+        Task UpdateAsync(Category category);
+        Task DeleteAsync(int id);
+        Task<bool> ExistsAsync(int id);
+    }
+}
diff --git a/SeaHaven.DataServices/Interfaces/IContactDataService.cs b/SeaHaven.DataServices/Interfaces/IContactDataService.cs
new file mode 100644
index 0000000..113d959
--- /dev/null
+++ b/SeaHaven.DataServices/Interfaces/IContactDataService.cs
@@ -0,0 +1,42 @@
+using Data.SeaHavenIndustries;
+
+namespace SeaHaven.DataServices.Interfaces
+{
+    /// <summary>
+    /// Data service interface for Contact entity
+    /// Handles all data access operations for Contacts
+    /// </summary>
+    public interface IContactDataService
+    {
+        // Query operations
+        Task<Contacts?> GetByIdAsync(int id);
+        Task<Contacts?> GetByIdWithDetailsAsync(int id);
+        Task<IEnumerable<Contacts>> GetAllAsync();
+        Task<IEnumerable<Contacts>> GetByAccountIdAsync(int accountId);
+        Task<IEnumerable<Contacts>> GetByTypeAsync(string type);
+        Task<Contacts?> GetByEmailAsync(string email);
+        Task<Contacts?> GetByPhoneAsync(string phone);
+        
+        // Paged results
+        Task<(IEnumerable<Contacts> Items, int TotalCount)> GetPagedAsync(
+            int page, 
+            int pageSize, 
+            string? search = null, 
+            string? type = null);
+        
+        // Command operations
+        Task<Contacts> AddAsync(Contacts contact);
+        Task UpdateAsync(Contacts contact);
+        Task DeleteAsync(int id);
+        
+        // Validation operations
+        Task<bool> ExistsAsync(int id);
+        Task<bool> EmailExistsAsync(string email, int? excludeId = null);
+        Task<bool> PhoneExistsAsync(string phone, int? excludeId = null);
+        
+        // Count operations
+        Task<int> CountAsync();
+        Task<int> CountByAccountIdAsync(int accountId);
+        Task<int> CountByTypeAsync(string type);
+    }
+}
diff --git a/SeaHaven.DataServices/Interfaces/IDispatchDataService.cs b/SeaHaven.DataServices/Interfaces/IDispatchDataService.cs
new file mode 100644
index 0000000..32ec4e0
--- /dev/null
+++ b/SeaHaven.DataServices/Interfaces/IDispatchDataService.cs
@@ -0,0 +1,20 @@
+using Data.SeaHavenIndustries;
+
+namespace SeaHaven.DataServices.Interfaces
+{
+    public interface IDispatchDataService
+    {
+        Task<Dispatch?> GetByIdAsync(int id);
+        Task<Dispatch?> GetByIdWithDetailsAsync(int id);
+        Task<IEnumerable<Dispatch>> GetAllAsync();
+        Task<IEnumerable<Dispatch>> GetByVendorIdAsync(int vendorId);
+        Task<IEnumerable<Dispatch>> GetByStatusAsync(string status);
+        Task<(IEnumerable<Dispatch> Items, int TotalCount)> GetPagedAsync(int page, int pageSize, string? search = null, string? status = null);
+        Task<Dispatch> AddAsync(Dispatch dispatch);
+        Task UpdateAsync(Dispatch dispatch);
+        Task DeleteAsync(int id);
+        Task<bool> ExistsAsync(int id);
+        Task<string> GenerateNextDispatchNumberAsync();
+        Task<int> CountAsync();
+    }
+}
diff --git a/SeaHaven.DataServices/Interfaces/IEmployeeDataService.cs b/SeaHaven.DataServices/Interfaces/IEmployeeDataService.cs
new file mode 100644
index 0000000..a743d0e
--- /dev/null
+++ b/SeaHaven.DataServices/Interfaces/IEmployeeDataService.cs
@@ -0,0 +1,17 @@
+using Data.SeaHavenIndustries;
+
+namespace SeaHaven.DataServices.Interfaces
+{
+    public interface IEmployeeDataService
+    {
+        Task<Employee?> GetByIdAsync(int id);
+        Task<Employee?> GetByIdWithDetailsAsync(int id);
+        Task<IEnumerable<Employee>> GetAllAsync();
+        Task<(IEnumerable<Employee> Items, int TotalCount)> GetPagedAsync(int page, int pageSize, string? search = null);
+        Task<Employee> AddAsync(Employee employee);
+        Task UpdateAsync(Employee employee);
+        Task DeleteAsync(int id);
+        Task<bool> ExistsAsync(int id);
+        Task<int> CountAsync();
+    }
+}
diff --git a/SeaHaven.DataServices/Interfaces/IFollowUpDataService.cs b/SeaHaven.DataServices/Interfaces/IFollowUpDataService.cs
new file mode 100644
index 0000000..c8b8df3
--- /dev/null
+++ b/SeaHaven.DataServices/Interfaces/IFollowUpDataService.cs
@@ -0,0 +1,19 @@
+using Data.SeaHavenIndustries;
+
+namespace SeaHaven.DataServices.Interfaces
+{
+    public interface IFollowUpDataService
+    {
+        Task<FollowUps?> GetByIdAsync(int id);
+        Task<FollowUps?> GetByIdWithDetailsAsync(int id);
+        Task<IEnumerable<FollowUps>> GetAllAsync();
+        Task<IEnumerable<FollowUps>> GetByWorkOrderIdAsync(int workOrderId);
+        Task<IEnumerable<FollowUps>> GetByUserIdAsync(string userId);
+        Task<(IEnumerable<FollowUps> Items, int TotalCount)> GetPagedAsync(int page, int pageSize, string? search = null, string? status = null);
+        Task<FollowUps> AddAsync(FollowUps followUp);
+        Task UpdateAsync(FollowUps followUp);
+        Task DeleteAsync(int id);
+        Task<bool> ExistsAsync(int id);
+        Task<int> CountAsync();
+    }
+}
diff --git a/SeaHaven.DataServices/Interfaces/ILocationDataService.cs b/SeaHaven.DataServices/Interfaces/ILocationDataService.cs
new file mode 100644
index 0000000..6f4d90a
--- /dev/null
+++ b/SeaHaven.DataServices/Interfaces/ILocationDataService.cs
@@ -0,0 +1,18 @@
+using Data.SeaHavenIndustries;
+
+namespace SeaHaven.DataServices.Interfaces
+{
+    public interface ILocationDataService
+    {
+        Task<Locations?> GetByIdAsync(int id);
+        Task<Locations?> GetByIdWithDetailsAsync(int id);
+        Task<IEnumerable<Locations>> GetAllAsync();
+        Task<IEnumerable<Locations>> GetByAccountIdAsync(int accountId);
+        Task<(IEnumerable<Locations> Items, int TotalCount)> GetPagedAsync(int page, int pageSize, string? search = null);
+        Task<Locations> AddAsync(Locations location);
+        Task UpdateAsync(Locations location);
+        Task DeleteAsync(int id);
+        Task<bool> ExistsAsync(int id);
+        Task<int> CountAsync();
+    }
+}
diff --git a/SeaHaven.DataServices/Interfaces/IPMScheduleDataService.cs b/SeaHaven.DataServices/Interfaces/IPMScheduleDataService.cs
new file mode 100644
index 0000000..f655777
--- /dev/null
+++ b/SeaHaven.DataServices/Interfaces/IPMScheduleDataService.cs
@@ -0,0 +1,18 @@
+using Data.SeaHavenIndustries;
+
+namespace SeaHaven.DataServices.Interfaces
+{
+    public interface IPMScheduleDataService
+    {
+        Task<PMSchedules?> GetByIdAsync(int id);
+        Task<PMSchedules?> GetByIdWithDetailsAsync(int id);
+        Task<IEnumerable<PMSchedules>> GetAllAsync();
+        Task<IEnumerable<PMSchedules>> GetByLocationIdAsync(int locationId);
+        Task<(IEnumerable<PMSchedules> Items, int TotalCount)> GetPagedAsync(int page, int pageSize, string? search = null);
+        Task<PMSchedules> AddAsync(PMSchedules pmSchedule);
+        Task UpdateAsync(PMSchedules pmSchedule);
+        Task DeleteAsync(int id);
+        Task<bool> ExistsAsync(int id);
+        Task<int> CountAsync();
+    }
+}
diff --git a/SeaHaven.DataServices/Interfaces/IVendorDataService.cs b/SeaHaven.DataServices/Interfaces/IVendorDataService.cs
new file mode 100644
index 0000000..6458b4f
--- /dev/null
+++ b/SeaHaven.DataServices/Interfaces/IVendorDataService.cs
@@ -0,0 +1,19 @@
+using Data.SeaHavenIndustries;
+
+namespace SeaHaven.DataServices.Interfaces
+{
+    public interface IVendorDataService
+    {
+        Task<Vendor?> GetByIdAsync(int id);
+        Task<Vendor?> GetByIdWithDetailsAsync(int id);
+        Task<IEnumerable<Vendor>> GetAllAsync();
+        Task<(IEnumerable<Vendor> Items, int TotalCount)> GetPagedAsync(int page, int pageSize, string? search = null);
+        Task<Vendor> AddAsync(Vendor vendor);
+        Task UpdateAsync(Vendor vendor);
+        Task DeleteAsync(int id);
+        Task<bool> ExistsAsync(int id);
+        Task<VendorAccessToken?> GetActiveTokenAsync(int vendorId);
+        Task<VendorAccessToken?> GetTokenByStringAsync(string token);
+        Task<int> CountAsync();
+    }
+}
diff --git a/SeaHaven.DataServices/Interfaces/IWorkOrderDataService.cs b/SeaHaven.DataServices/Interfaces/IWorkOrderDataService.cs
new file mode 100644
index 0000000..1e70a27
--- /dev/null
+++ b/SeaHaven.DataServices/Interfaces/IWorkOrderDataService.cs
@@ -0,0 +1,48 @@
+using Data.SeaHavenIndustries;
+
+namespace SeaHaven.DataServices.Interfaces
+{
+    public interface IWorkOrderDataService
+    {
+        // Query operations
+        Task<WorkOrder?> GetByIdAsync(int id);
+        Task<WorkOrder?> GetByIdWithDetailsAsync(int id);
+        Task<WorkOrder?> GetByInternalNumberAsync(string internalNumber);
+        Task<IEnumerable<WorkOrder>> GetAllAsync();
+        Task<IEnumerable<WorkOrder>> GetByLocationIdAsync(int locationId);
+        Task<IEnumerable<WorkOrder>> GetByAssigneeAsync(string assigneeId);
+        Task<IEnumerable<WorkOrder>> GetByStatusAsync(string status);
+        Task<IEnumerable<WorkOrder>> GetByPriorityAsync(string priority);
+        
+        // Paged results
+        Task<(IEnumerable<WorkOrder> Items, int TotalCount)> GetPagedAsync(
+            int page, 
+            int pageSize, 
+            string? search = null, 
+            string? status = null,
+            string? priority = null);
+        
+        // Command operations
+        Task<WorkOrder> AddAsync(WorkOrder workOrder);
+        Task UpdateAsync(WorkOrder workOrder);
+        Task DeleteAsync(int id);
+        
+        // Related entities
+        Task<IEnumerable<WorkOrderContacts>> GetWorkOrderContactsAsync(int workOrderId);
+        Task<IEnumerable<WorkOrderCategories>> GetWorkOrderCategoriesAsync(int workOrderId);
+        Task<IEnumerable<WorkOrderAttachments>> GetWorkOrderAttachmentsAsync(int workOrderId);
+        Task<IEnumerable<Comments>> GetWorkOrderCommentsAsync(int workOrderId);
+        
+        // Validation
+        Task<bool> ExistsAsync(int id);
+        Task<bool> InternalNumberExistsAsync(string internalNumber, int? excludeId = null);
+        
+        // Internal number generation
+        Task<string> GenerateNextInternalWONumberAsync();
+        
+        // Statistics
+        Task<int> CountAsync();
+        Task<int> CountByStatusAsync(string status);
+        Task<int> CountByLocationAsync(int locationId);
+    }
+}
diff --git a/SeaHaven.DataServices/SeaHaven.DataServices.csproj b/SeaHaven.DataServices/SeaHaven.DataServices.csproj
new file mode 100644
index 0000000..37cd429
--- /dev/null
+++ b/SeaHaven.DataServices/SeaHaven.DataServices.csproj
@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Data.SeaHavenIndustries\Data.SeaHavenIndustries.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.8" />
+  </ItemGroup>
+
+</Project>
diff --git a/SeaHaven.Services/DTOs/AccountDTOs.cs b/SeaHaven.Services/DTOs/AccountDTOs.cs
new file mode 100644
index 0000000..662a9ee
--- /dev/null
+++ b/SeaHaven.Services/DTOs/AccountDTOs.cs
@@ -0,0 +1,29 @@
+namespace SeaHaven.Services.DTOs
+{
+    public class AccountDTO
+    {
+        public int Id { get; set; }
+        public string? Name { get; set; }
+        public string? Phone { get; set; }
+        public string? Email { get; set; }
+        public string? Website { get; set; }
+        public DateTime? CreatedDate { get; set; }
+        public string? CreatedBy { get; set; }
+    }
+
+    public class CreateAccountDTO
+    {
+        public required string Name { get; set; }
+        public string? Phone { get; set; }
+        public string? Email { get; set; }
+        public string? Website { get; set; }
+    }
+
+    public class UpdateAccountDTO
+    {
+        public string? Name { get; set; }
+        public string? Phone { get; set; }
+        public string? Email { get; set; }
+        public string? Website { get; set; }
+    }
+}
diff --git a/SeaHaven.Services/DTOs/AssetDTOs.cs b/SeaHaven.Services/DTOs/AssetDTOs.cs
new file mode 100644
index 0000000..cd8eb76
--- /dev/null
+++ b/SeaHaven.Services/DTOs/AssetDTOs.cs
@@ -0,0 +1,29 @@
+namespace SeaHaven.Services.DTOs
+{
+    public class AssetDTO
+    {
+        public int Id { get; set; }
+        public string? Name { get; set; }
+        public string? Type { get; set; }
+        public string? SerialNumber { get; set; }
+        public int? LocationId { get; set; }
+        public string? LocationName { get; set; }
+        public DateTime? CreatedDate { get; set; }
+    }
+
+    public class CreateAssetDTO
+    {
+        public required string Name { get; set; }
+        public string? Type { get; set; }
+        public string? SerialNumber { get; set; }
+        public int? LocationId { get; set; }
+    }
+
+    public class UpdateAssetDTO
+    {
+        public string? Name { get; set; }
+        public string? Type { get; set; }
+        public string? SerialNumber { get; set; }
+        public int? LocationId { get; set; }
+    }
+}
diff --git a/SeaHaven.Services/DTOs/ContactDTOs.cs b/SeaHaven.Services/DTOs/ContactDTOs.cs
new file mode 100644
index 0000000..ac7bb19
--- /dev/null
+++ b/SeaHaven.Services/DTOs/ContactDTOs.cs
@@ -0,0 +1,67 @@
+namespace SeaHaven.Services.DTOs
+{
+    /// <summary>
+    /// Contact DTO for responses
+    /// </summary>
+    public class ContactDTO
+    {
+        public int Id { get; set; }
+        public string? FirstName { get; set; }
+        public string? LastName { get; set; }
+        public string? Email { get; set; }
+        public string? Phone { get; set; }
+        public string? Mobile { get; set; }
+        public string? Title { get; set; }
+        public string? Type { get; set; }
+        public int? AccountId { get; set; }
+        public string? AccountName { get; set; }
+        public DateTime? CreatedDate { get; set; }
+        public string? CreatedBy { get; set; }
+        public DateTime? ModifiedDate { get; set; }
+        public string? ModifiedBy { get; set; }
+    }
+
+    /// <summary>
+    /// DTO for creating a new contact
+    /// </summary>
+    public class CreateContactDTO
+    {
+        public required string FirstName { get; set; }
+        public required string LastName { get; set; }
+        public required string Email { get; set; }
+        public string? Phone { get; set; }
+        public string? Mobile { get; set; }
+        public string? Title { get; set; }
+        public string? Type { get; set; }
+        public int? AccountId { get; set; }
+    }
+
+    /// <summary>
+    /// DTO for updating an existing contact
+    /// </summary>
+    public class UpdateContactDTO
+    {
+        public string? FirstName { get; set; }
+        public string? LastName { get; set; }
+        public string? Email { get; set; }
+        public string? Phone { get; set; }
+        public string? Mobile { get; set; }
+        public string? Title { get; set; }
+        public string? Type { get; set; }
+        public int? AccountId { get; set; }
+    }
+
+    /// <summary>
+    /// Paged result wrapper
+    /// </summary>
+    public class PagedResult<T>
+    {
+        public IEnumerable<T> Items { get; set; } = new List<T>();
+        public int TotalCount { get; set; }
+        public int Page { get; set; }
+        public int PageSize { get; set; }
+        public int TotalPages => (int)Math.Ceiling(TotalCount / (double)PageSize);
+        public bool HasPrevious => Page > 1;
+        public bool HasNext => Page < TotalPages;
+    }
+}
diff --git a/SeaHaven.Services/DTOs/DispatchDTOs.cs b/SeaHaven.Services/DTOs/DispatchDTOs.cs
new file mode 100644
index 0000000..49a4a53
--- /dev/null
+++ b/SeaHaven.Services/DTOs/DispatchDTOs.cs
@@ -0,0 +1,30 @@
+namespace SeaHaven.Services.DTOs
+{
+    public class DispatchDTO
+    {
+        public int Id { get; set; }
+        public string? DispatchNumber { get; set; }
+        public string? Status { get; set; }
+        public int? VendorId { get; set; }
+        public string? VendorName { get; set; }
+        public DateTime? ScheduledDate { get; set; }
+        public DateTime? CompletedDate { get; set; }
+        public DateTime? CreatedDate { get; set; }
+        public string? CreatedBy { get; set; }
+    }
+
+    public class CreateDispatchDTO
+    {
+        public required int VendorId { get; set; }
+        public DateTime? ScheduledDate { get; set; }
+        public string? Status { get; set; }
+    }
+
+    public class UpdateDispatchDTO
+    {
+        public int? VendorId { get; set; }
+        public DateTime? ScheduledDate { get; set; }
+        public DateTime? CompletedDate { get; set; }
+        public string? Status { get; set; }
+    }
+}
diff --git a/SeaHaven.Services/DTOs/EmployeeDTOs.cs b/SeaHaven.Services/DTOs/EmployeeDTOs.cs
new file mode 100644
index 0000000..ca78e85
--- /dev/null
+++ b/SeaHaven.Services/DTOs/EmployeeDTOs.cs
@@ -0,0 +1,40 @@
+namespace SeaHaven.Services.DTOs
+{
+    public class EmployeeDTO
+    {
+        public int Id { get; set; }
+        public string? FirstName { get; set; }
+        public string? LastName { get; set; }
+        public string? Email { get; set; }
+        public string? Phone { get; set; }
+        public int? DepartmentId { get; set; }
+        public string? DepartmentName { get; set; }
+        public int? JobTitleId { get; set; }
+        public string? JobTitleName { get; set; }
+        public int? RegionId { get; set; }
+        public string? RegionName { get; set; }
+        public DateTime? CreatedDate { get; set; }
+    }
+
+    public class CreateEmployeeDTO
+    {
+        public required string FirstName { get; set; }
+        public required string LastName { get; set; }
+        public string? Email { get; set; }
+        public string? Phone { get; set; }
+        public int? DepartmentId { get; set; }
+        public int? JobTitleId { get; set; }
+        public int? RegionId { get; set; }
+    }
+
+    public class UpdateEmployeeDTO
+    {
+        public string? FirstName { get; set; }
+        public string? LastName { get; set; }
+        public string? Email { get; set; }
+        public string? Phone { get; set; }
+        public int? DepartmentId { get; set; }
+        public int? JobTitleId { get; set; }
+        public int? RegionId { get; set; }
+    }
+}
diff --git a/SeaHaven.Services/DTOs/FollowUpDTOs.cs b/SeaHaven.Services/DTOs/FollowUpDTOs.cs
new file mode 100644
index 0000000..23668a6
--- /dev/null
+++ b/SeaHaven.Services/DTOs/FollowUpDTOs.cs
@@ -0,0 +1,34 @@
+namespace SeaHaven.Services.DTOs
+{
+    public class FollowUpDTO
+    {
+        public int Id { get; set; }
+        public string? Subject { get; set; }
+        public string? Description { get; set; }
+        public string? Status { get; set; }
+        public int? WorkOrderId { get; set; }
+        public string? AssignedTo { get; set; }
+        public DateTime? DueDate { get; set; }
+        public DateTime? CreatedDate { get; set; }
+        public string? CreatedBy { get; set; }
+    }
+
+    public class CreateFollowUpDTO
+    {
+        public required string Subject { get; set; }
+        public string? Description { get; set; }
+        public string? Status { get; set; }
+        public int? WorkOrderId { get; set; }
+        public string? AssignedTo { get; set; }
+        public DateTime? DueDate { get; set; }
+    }
+
+    public class UpdateFollowUpDTO
+    {
+        public string? Subject { get; set; }
+        public string? Description { get; set; }
+        public string? Status { get; set; }
+        public string? AssignedTo { get; set; }
+        public DateTime? DueDate { get; set; }
+    }
+}
diff --git a/SeaHaven.Services/DTOs/LocationDTOs.cs b/SeaHaven.Services/DTOs/LocationDTOs.cs
new file mode 100644
index 0000000..2e33eb7
--- /dev/null
+++ b/SeaHaven.Services/DTOs/LocationDTOs.cs
@@ -0,0 +1,36 @@
+namespace SeaHaven.Services.DTOs
+{
+    public class LocationDTO
+    {
+        public int Id { get; set; }
+        public string? LocationName { get; set; }
+        public string? Address { get; set; }
+        public string? City { get; set; }
+        public string? State { get; set; }
+        public string? Zipcode { get; set; }
+        public int? AccountId { get; set; }
+        public string? AccountName { get; set; }
+        public DateTime? CreatedDate { get; set; }
+        public string? CreatedBy { get; set; }
+    }
+
+    public class CreateLocationDTO
+    {
+        public required string LocationName { get; set; }
+        public string? Address { get; set; }
+        public string? City { get; set; }
+        public string? State { get; set; }
+        public string? Zipcode { get; set; }
+        public int? AccountId { get; set; }
+    }
+
+    public class UpdateLocationDTO
+    {
+        public string? LocationName { get; set; }
+        public string? Address { get; set; }
+        public string? City { get; set; }
+        public string? State { get; set; }
+        public string? Zipcode { get; set; }
+        public int? AccountId { get; set; }
+    }
+}
diff --git a/SeaHaven.Services/DTOs/PMScheduleDTOs.cs b/SeaHaven.Services/DTOs/PMScheduleDTOs.cs
new file mode 100644
index 0000000..7c0daf5
--- /dev/null
+++ b/SeaHaven.Services/DTOs/PMScheduleDTOs.cs
@@ -0,0 +1,32 @@
+namespace SeaHaven.Services.DTOs
+{
+    public class PMScheduleDTO
+    {
+        public int Id { get; set; }
+        public string? Name { get; set; }
+        public string? Description { get; set; }
+        public int? LocationId { get; set; }
+        public string? LocationName { get; set; }
+        public string? Frequency { get; set; }
+        public DateTime? NextDueDate { get; set; }
+        public DateTime? CreatedDate { get; set; }
+    }
+
+    public class CreatePMScheduleDTO
+    {
+        public required string Name { get; set; }
+        public string? Description { get; set; }
+        public int? LocationId { get; set; }
+        public string? Frequency { get; set; }
+        public DateTime? NextDueDate { get; set; }
+    }
+
+    public class UpdatePMScheduleDTO
+    {
+        public string? Name { get; set; }
+        public string? Description { get; set; }
+        public int? LocationId { get; set; }
+        public string? Frequency { get; set; }
+        public DateTime? NextDueDate { get; set; }
+    }
+}
diff --git a/SeaHaven.Services/DTOs/VendorDTOs.cs b/SeaHaven.Services/DTOs/VendorDTOs.cs
new file mode 100644
index 0000000..3a58934
--- /dev/null
+++ b/SeaHaven.Services/DTOs/VendorDTOs.cs
@@ -0,0 +1,36 @@
+namespace SeaHaven.Services.DTOs
+{
+    public class VendorDTO
+    {
+        public int Id { get; set; }
+        public string? Name { get; set; }
+        public string? Email { get; set; }
+        public string? Phone { get; set; }
+        public string? Address { get; set; }
+        public string? City { get; set; }
+        public string? State { get; set; }
+        public string? Zipcode { get; set; }
+    }
+
+    public class CreateVendorDTO
+    {
+        public required string Name { get; set; }
+        public string? Email { get; set; }
+        public string? Phone { get; set; }
+        public string? Address { get; set; }
+        public string? City { get; set; }
+        public string? State { get; set; }
+        public string? Zipcode { get; set; }
+    }
+
+    public class UpdateVendorDTO
+    {
+        public string? Name { get; set; }
+        public string? Email { get; set; }
+        public string? Phone { get; set; }
+        public string? Address { get; set; }
+        public string? City { get; set; }
+        public string? State { get; set; }
+        public string? Zipcode { get; set; }
+    }
+}
diff --git a/SeaHaven.Services/DTOs/WorkOrderDTOs.cs b/SeaHaven.Services/DTOs/WorkOrderDTOs.cs
new file mode 100644
index 0000000..c5f9a0f
--- /dev/null
+++ b/SeaHaven.Services/DTOs/WorkOrderDTOs.cs
@@ -0,0 +1,44 @@
+namespace SeaHaven.Services.DTOs
+{
+    public class WorkOrderDTO
+    {
+        public int Id { get; set; }
+        public string? InternalWONumber { get; set; }
+        public string? WorkerOrderTitle { get; set; }
+        public string? Description { get; set; }
+        public string? Status { get; set; }
+        public string? Priority { get; set; }
+        public int? LocationId { get; set; }
+        public string? LocationName { get; set; }
+        public string? AssignTo { get; set; }
+        public DateTime? DueDate { get; set; }
+        public DateTime? CompletedDate { get; set; }
+        public DateTime? CreatedDate { get; set; }
+        public string? CreatedBy { get; set; }
+        public DateTime? ModifiedDate { get; set; }
+        public string? ModifiedBy { get; set; }
+    }
+
+    public class CreateWorkOrderDTO
+    {
+        public required string WorkerOrderTitle { get; set; }
+        public string? Description { get; set; }
+        public string? Status { get; set; }
+        public string? Priority { get; set; }
+        public int? LocationId { get; set; }
+        public string? AssignTo { get; set; }
+        public DateTime? DueDate { get; set; }
+    }
+
+    public class UpdateWorkOrderDTO
+    {
+        public string? WorkerOrderTitle { get; set; }
+        public string? Description { get; set; }
+        public string? Status { get; set; }
+        public string? Priority { get; set; }
+        public int? LocationId { get; set; }
+        public string? AssignTo { get; set; }
+        public DateTime? DueDate { get; set; }
+        public DateTime? CompletedDate { get; set; }
+    }
+}
diff --git a/SeaHaven.Services/Implementation/ContactService.cs b/SeaHaven.Services/Implementation/ContactService.cs
new file mode 100644
index 0000000..dcbcc35
--- /dev/null
+++ b/SeaHaven.Services/Implementation/ContactService.cs
@@ -0,0 +1,220 @@
+using Data.SeaHavenIndustries;
+using SeaHaven.DataServices.Interfaces;
+using SeaHaven.Services.DTOs;
+using SeaHaven.Services.Interfaces;
+
+namespace SeaHaven.Services.Implementation
+{
+    /// <summary>
+    /// Contact service implementation
+    /// Contains business logic, validation, and orchestration for Contact operations
+    /// </summary>
+    public class ContactService : IContactService
+    {
+        private readonly IContactDataService _contactDataService;
+
+        public ContactService(IContactDataService contactDataService)
+        {
+            _contactDataService = contactDataService;
+        }
+
+        // Query operations
+        public async Task<ContactDTO?> GetContactByIdAsync(int id)
+        {
+            var contact = await _contactDataService.GetByIdAsync(id);
+            return contact == null ? null : MapToDTO(contact);
+        }
+
+        public async Task<ContactDTO?> GetContactByIdWithDetailsAsync(int id)
+        {
+            var contact = await _contactDataService.GetByIdWithDetailsAsync(id);
+            return contact == null ? null : MapToDTO(contact);
+        }
+
+        public async Task<IEnumerable<ContactDTO>> GetAllContactsAsync()
+        {
+            var contacts = await _contactDataService.GetAllAsync();
+            return contacts.Select(MapToDTO);
+        }
+
+        public async Task<IEnumerable<ContactDTO>> GetContactsByAccountIdAsync(int accountId)
+        {
+            var contacts = await _contactDataService.GetByAccountIdAsync(accountId);
+            return contacts.Select(MapToDTO);
+        }
+
+        public async Task<IEnumerable<ContactDTO>> GetContactsByTypeAsync(string type)
+        {
+            var contacts = await _contactDataService.GetByTypeAsync(type);
+            return contacts.Select(MapToDTO);
+        }
+
+        public async Task<ContactDTO?> GetContactByEmailAsync(string email)
+        {
+            var contact = await _contactDataService.GetByEmailAsync(email);
+            return contact == null ? null : MapToDTO(contact);
+        }
+
+        // Paged results
+        public async Task<PagedResult<ContactDTO>> GetContactsPagedAsync(
+            int page,
+            int pageSize,
+            string? search = null,
+            string? type = null)
+        {
+            var (items, totalCount) = await _contactDataService.GetPagedAsync(page, pageSize, search, type);
+
+            return new PagedResult<ContactDTO>
+            {
+                Items = items.Select(MapToDTO),
+                TotalCount = totalCount,
+                Page = page,
+                PageSize = pageSize
+            };
+        }
+
+        // Command operations
+        public async Task<ContactDTO> CreateContactAsync(CreateContactDTO dto, string userId)
+        {
+            // Validation
+            if (string.IsNullOrWhiteSpace(dto.Email))
+                throw new ArgumentException("Email is required", nameof(dto.Email));
+
+            if (await _contactDataService.EmailExistsAsync(dto.Email))
+                throw new InvalidOperationException($"Email '{dto.Email}' already exists");
+
+            // Map DTO to entity
+            var contact = new Contacts
+            {
+                FirstName = dto.FirstName,
+                LastName = dto.LastName,
+                Email = dto.Email,
+                PhoneNumber = dto.Phone ?? dto.Mobile, // Contacts only has PhoneNumber, not separate Mobile
+                Title = dto.Title,
+                ContactType = dto.Type,
+                AccountId = dto.AccountId,
+                createdby = userId,
+                CreatedDate = DateTime.Now
+            };
+
+            // Save
+            var savedContact = await _contactDataService.AddAsync(contact);
+
+            return MapToDTO(savedContact);
+        }
+
+        public async Task<ContactDTO> UpdateContactAsync(int id, UpdateContactDTO dto, string userId)
+        {
+            // Check if exists
+            var existingContact = await _contactDataService.GetByIdAsync(id);
+            if (existingContact == null)
+                throw new KeyNotFoundException($"Contact with ID {id} not found");
+
+            // Validate email uniqueness if changed
+            if (!string.IsNullOrWhiteSpace(dto.Email) && dto.Email != existingContact.Email)
+            {
+                if (await _contactDataService.EmailExistsAsync(dto.Email, id))
+                    throw new InvalidOperationException($"Email '{dto.Email}' already exists");
+            }
+
+            // Update fields
+            if (!string.IsNullOrWhiteSpace(dto.FirstName))
+                existingContact.FirstName = dto.FirstName;
+
+            if (!string.IsNullOrWhiteSpace(dto.LastName))
+                existingContact.LastName = dto.LastName;
+
+            if (!string.IsNullOrWhiteSpace(dto.Email))
+                existingContact.Email = dto.Email;
+
+            if (dto.Phone != null || dto.Mobile != null)
+                existingContact.PhoneNumber = dto.Phone ?? dto.Mobile; // Contacts only has PhoneNumber
+
+            if (dto.Title != null)
+                existingContact.Title = dto.Title;
+
+            if (dto.Type != null)
+                existingContact.ContactType = dto.Type;
+
+            if (dto.AccountId.HasValue)
+                existingContact.AccountId = dto.AccountId;
+
+            existingContact.LastModificationTime = DateTime.Now;
+
+            // Save
+            await _contactDataService.UpdateAsync(existingContact);
+
+            return MapToDTO(existingContact);
+        }
+
+        public async Task DeleteContactAsync(int id, string userId)
+        {
+            // Check if exists
+            if (!await _contactDataService.ExistsAsync(id))
+                throw new KeyNotFoundException($"Contact with ID {id} not found");
+
+            // Business logic: Check if contact is being used (add your logic here)
+            // For example, check if contact is linked to work orders, etc.
+
+            await _contactDataService.DeleteAsync(id);
+        }
+
+        // Validation operations
+        public async Task<bool> ContactExistsAsync(int id)
+        {
+            return await _contactDataService.ExistsAsync(id);
+        }
+
+        public async Task<bool> EmailExistsAsync(string email, int? excludeId = null)
+        {
+            return await _contactDataService.EmailExistsAsync(email, excludeId);
+        }
+
+        public async Task<bool> PhoneExistsAsync(string phone, int? excludeId = null)
+        {
+            return await _contactDataService.PhoneExistsAsync(phone, excludeId);
+        }
+
+        // Statistics
+        public async Task<int> GetTotalContactCountAsync()
+        {
+            return await _contactDataService.CountAsync();
+        }
+
+        public async Task<int> GetContactCountByAccountAsync(int accountId)
+        {
+            return await _contactDataService.CountByAccountIdAsync(accountId);
+        }
+
+        public async Task<Dictionary<string, int>> GetContactCountByTypeAsync()
+        {
+            var contacts = await _contactDataService.GetAllAsync();
+            return contacts
+                .Where(c => !string.IsNullOrWhiteSpace(c.ContactType))
+                .GroupBy(c => c.ContactType!)
+                .ToDictionary(g => g.Key, g => g.Count());
+        }
+
+        // Private mapping methods
+        private static ContactDTO MapToDTO(Contacts contact)
+        {
+            return new ContactDTO
+            {
+                Id = contact.Id,
+                FirstName = contact.FirstName,
+                LastName = contact.LastName,
+                Email = contact.Email,
+                Phone = contact.PhoneNumber,
+                Mobile = contact.PhoneNumber, // Contacts only has one PhoneNumber field
+                Title = contact.Title,
+                Type = contact.ContactType,
+                AccountId = contact.AccountId,
+                AccountName = contact.Account?.Name,
+                CreatedDate = contact.CreatedDate,
+                CreatedBy = contact.createdby,
+                ModifiedDate = contact.LastModificationTime,
+                ModifiedBy = null // Not tracked in FullAuditEntity
+            };
+        }
+    }
+}
diff --git a/SeaHaven.Services/Implementation/WorkOrderService.cs b/SeaHaven.Services/Implementation/WorkOrderService.cs
new file mode 100644
index 0000000..17b5f64
--- /dev/null
+++ b/SeaHaven.Services/Implementation/WorkOrderService.cs
@@ -0,0 +1,142 @@
+using Data.SeaHavenIndustries;
+using SeaHaven.DataServices.Interfaces;
+using SeaHaven.Services.DTOs;
+using SeaHaven.Services.Interfaces;
+
+namespace SeaHaven.Services.Implementation
+{
+    public class WorkOrderService : IWorkOrderService
+    {
+        private readonly IWorkOrderDataService _workOrderDataService;
+
+        public WorkOrderService(IWorkOrderDataService workOrderDataService)
+        {
+            _workOrderDataService = workOrderDataService;
+        }
+
+        public async Task<WorkOrderDTO?> GetWorkOrderByIdAsync(int id)
+        {
+            var workOrder = await _workOrderDataService.GetByIdAsync(id);
+            return workOrder == null ? null : MapToDTO(workOrder);
+        }
+
+        public async Task<WorkOrderDTO?> GetWorkOrderByIdWithDetailsAsync(int id)
+        {
+            var workOrder = await _workOrderDataService.GetByIdWithDetailsAsync(id);
+            return workOrder == null ? null : MapToDTO(workOrder);
+        }
+
+        public async Task<IEnumerable<WorkOrderDTO>> GetAllWorkOrdersAsync()
+        {
+            var workOrders = await _workOrderDataService.GetAllAsync();
+            return workOrders.Select(MapToDTO);
+        }
+
+        public async Task<PagedResult<WorkOrderDTO>> GetWorkOrdersPagedAsync(int page, int pageSize, string? search = null, string? status = null, string? priority = null)
+        {
+            var (items, totalCount) = await _workOrderDataService.GetPagedAsync(page, pageSize, search, status, priority);
+            return new PagedResult<WorkOrderDTO>
+            {
+                Items = items.Select(MapToDTO),
+                TotalCount = totalCount,
+                Page = page,
+                PageSize = pageSize
+            };
+        }
+
+        public async Task<WorkOrderDTO> CreateWorkOrderAsync(CreateWorkOrderDTO dto, string userId)
+        {
+            var workOrder = new WorkOrder
+            {
+                WorkerOrderTitle = dto.WorkerOrderTitle,
+                Description = dto.Description,
+                Status = dto.Status ?? "Open",
+                Priority = dto.Priority,
+                LocationId = dto.LocationId,
+                AssignTo = dto.AssignTo,
+                DueDate = dto.DueDate,
+                createdby = userId,
+                CreatedDate = DateTime.Now
+            };
+
+            // Generate internal number
+            workOrder.InternalWONumber = await _workOrderDataService.GenerateNextInternalWONumberAsync();
+
+            var savedWorkOrder = await _workOrderDataService.AddAsync(workOrder);
+            return MapToDTO(savedWorkOrder);
+        }
+
+        public async Task<WorkOrderDTO> UpdateWorkOrderAsync(int id, UpdateWorkOrderDTO dto, string userId)
+        {
+            var existingWorkOrder = await _workOrderDataService.GetByIdAsync(id);
+            if (existingWorkOrder == null)
+                throw new KeyNotFoundException($"WorkOrder with ID {id} not found");
+
+            if (!string.IsNullOrWhiteSpace(dto.WorkerOrderTitle))
+                existingWorkOrder.WorkerOrderTitle = dto.WorkerOrderTitle;
+            if (dto.Description != null)
+                existingWorkOrder.Description = dto.Description;
+            if (dto.Status != null)
+                existingWorkOrder.Status = dto.Status;
+            if (dto.Priority != null)
+                existingWorkOrder.Priority = dto.Priority;
+            if (dto.LocationId.HasValue)
+                existingWorkOrder.LocationId = dto.LocationId;
+            if (dto.AssignTo != null)
+                existingWorkOrder.AssignTo = dto.AssignTo;
+            if (dto.DueDate.HasValue)
+                existingWorkOrder.DueDate = dto.DueDate;
+            if (dto.CompletedDate.HasValue)
+                existingWorkOrder.CompletedDate = dto.CompletedDate;
+
+            existingWorkOrder.LastModificationTime = DateTime.Now;
+
+            await _workOrderDataService.UpdateAsync(existingWorkOrder);
+            return MapToDTO(existingWorkOrder);
+        }
+
+        public async Task DeleteWorkOrderAsync(int id, string userId)
+        {
+            if (!await _workOrderDataService.ExistsAsync(id))
+                throw new KeyNotFoundException($"WorkOrder with ID {id} not found");
+            await _workOrderDataService.DeleteAsync(id);
+        }
+
+        public async Task<bool> WorkOrderExistsAsync(int id)
+        {
+            return await _workOrderDataService.ExistsAsync(id);
+        }
+
+        public async Task<string> GenerateNextInternalWONumberAsync()
+        {
+            return await _workOrderDataService.GenerateNextInternalWONumberAsync();
+        }
+
+        public async Task<int> GetTotalWorkOrderCountAsync()
+        {
+            return await _workOrderDataService.CountAsync();
+        }
+
+        private static WorkOrderDTO MapToDTO(WorkOrder workOrder)
+        {
+            return new WorkOrderDTO
+            {
+                Id = workOrder.Id,
+                InternalWONumber = workOrder.InternalWONumber,
+                WorkerOrderTitle = workOrder.WorkerOrderTitle,
+                Description = workOrder.Description,
+                Status = workOrder.Status,
+                Priority = workOrder.Priority,
+                LocationId = workOrder.LocationId,
+                LocationName = workOrder.Locations?.Name,
+                AssignTo = workOrder.AssignTo,
+                DueDate = workOrder.DueDate,
+                CompletedDate = workOrder.CompletedDate,
+                CreatedDate = workOrder.CreatedDate,
+                CreatedBy = workOrder.createdby,
+                ModifiedDate = workOrder.LastModificationTime,
+                ModifiedBy = null // Not tracked in FullAuditEntity
+            };
+        }
+    }
+}
diff --git a/SeaHaven.Services/Interfaces/IAccountService.cs b/SeaHaven.Services/Interfaces/IAccountService.cs
new file mode 100644
index 0000000..84b68fb
--- /dev/null
+++ b/SeaHaven.Services/Interfaces/IAccountService.cs
@@ -0,0 +1,17 @@
+using SeaHaven.Services.DTOs;
+
+namespace SeaHaven.Services.Interfaces
+{
+    public interface IAccountService
+    {
+        Task<AccountDTO?> GetAccountByIdAsync(int id);
+        Task<AccountDTO?> GetAccountByIdWithDetailsAsync(int id);
+        Task<IEnumerable<AccountDTO>> GetAllAccountsAsync();
+        Task<PagedResult<AccountDTO>> GetAccountsPagedAsync(int page, int pageSize, string? search = null);
+        Task<AccountDTO> CreateAccountAsync(CreateAccountDTO dto, string userId);
+        Task<AccountDTO> UpdateAccountAsync(int id, UpdateAccountDTO dto, string userId);
+        Task DeleteAccountAsync(int id, string userId);
+        Task<bool> AccountExistsAsync(int id);
+        Task<int> GetTotalAccountCountAsync();
+    }
+}
diff --git a/SeaHaven.Services/Interfaces/IAssetService.cs b/SeaHaven.Services/Interfaces/IAssetService.cs
new file mode 100644
index 0000000..cf44fba
--- /dev/null
+++ b/SeaHaven.Services/Interfaces/IAssetService.cs
@@ -0,0 +1,18 @@
+using SeaHaven.Services.DTOs;
+
+namespace SeaHaven.Services.Interfaces
+{
+    public interface IAssetService
+    {
+        Task<AssetDTO?> GetAssetByIdAsync(int id);
+        Task<AssetDTO?> GetAssetByIdWithDetailsAsync(int id);
+        Task<IEnumerable<AssetDTO>> GetAllAssetsAsync();
+        Task<IEnumerable<AssetDTO>> GetAssetsByLocationIdAsync(int locationId);
+        Task<PagedResult<AssetDTO>> GetAssetsPagedAsync(int page, int pageSize, string? search = null);
+        Task<AssetDTO> CreateAssetAsync(CreateAssetDTO dto, string userId);
+        Task<AssetDTO> UpdateAssetAsync(int id, UpdateAssetDTO dto, string userId);
+        Task DeleteAssetAsync(int id, string userId);
+        Task<bool> AssetExistsAsync(int id);
+        Task<int> GetTotalAssetCountAsync();
+    }
+}
diff --git a/SeaHaven.Services/Interfaces/IContactService.cs b/SeaHaven.Services/Interfaces/IContactService.cs
new file mode 100644
index 0000000..15192cd
--- /dev/null
+++ b/SeaHaven.Services/Interfaces/IContactService.cs
@@ -0,0 +1,41 @@
+using SeaHaven.Services.DTOs;
+
+namespace SeaHaven.Services.Interfaces
+{
+    /// <summary>
+    /// Contact business service interface
+    /// Handles business logic, validation, and orchestration for Contact operations
+    /// </summary>
+    public interface IContactService
+    {
+        // Query operations
+        Task<ContactDTO?> GetContactByIdAsync(int id);
+        Task<ContactDTO?> GetContactByIdWithDetailsAsync(int id);
+        Task<IEnumerable<ContactDTO>> GetAllContactsAsync();
+        Task<IEnumerable<ContactDTO>> GetContactsByAccountIdAsync(int accountId);
+        Task<IEnumerable<ContactDTO>> GetContactsByTypeAsync(string type);
+        Task<ContactDTO?> GetContactByEmailAsync(string email);
+        
+        // Paged results
+        Task<PagedResult<ContactDTO>> GetContactsPagedAsync(
+            int page, 
+            int pageSize, 
+            string? search = null, 
+            string? type = null);
+        
+        // Command operations
+        Task<ContactDTO> CreateContactAsync(CreateContactDTO dto, string userId);
+        Task<ContactDTO> UpdateContactAsync(int id, UpdateContactDTO dto, string userId);
+        Task DeleteContactAsync(int id, string userId);
+        
+        // Validation operations
+        Task<bool> ContactExistsAsync(int id);
+        Task<bool> EmailExistsAsync(string email, int? excludeId = null);
+        Task<bool> PhoneExistsAsync(string phone, int? excludeId = null);
+        
+        // Statistics
+        Task<int> GetTotalContactCountAsync();
+        Task<int> GetContactCountByAccountAsync(int accountId);
+        Task<Dictionary<string, int>> GetContactCountByTypeAsync();
+    }
+}
diff --git a/SeaHaven.Services/Interfaces/IDispatchService.cs b/SeaHaven.Services/Interfaces/IDispatchService.cs
new file mode 100644
index 0000000..a650389
--- /dev/null
+++ b/SeaHaven.Services/Interfaces/IDispatchService.cs
@@ -0,0 +1,19 @@
+using SeaHaven.Services.DTOs;
+
+namespace SeaHaven.Services.Interfaces
+{
+    public interface IDispatchService
+    {
+        Task<DispatchDTO?> GetDispatchByIdAsync(int id);
+        Task<DispatchDTO?> GetDispatchByIdWithDetailsAsync(int id);
+        Task<IEnumerable<DispatchDTO>> GetAllDispatchesAsync();
+        Task<IEnumerable<DispatchDTO>> GetDispatchesByVendorIdAsync(int vendorId);
+        Task<PagedResult<DispatchDTO>> GetDispatchesPagedAsync(int page, int pageSize, string? search = null, string? status = null);
+        Task<DispatchDTO> CreateDispatchAsync(CreateDispatchDTO dto, string userId);
+        Task<DispatchDTO> UpdateDispatchAsync(int id, UpdateDispatchDTO dto, string userId);
+        Task DeleteDispatchAsync(int id, string userId);
+        Task<bool> DispatchExistsAsync(int id);
+        Task<string> GenerateNextDispatchNumberAsync();
+        Task<int> GetTotalDispatchCountAsync();
+    }
+}
diff --git a/SeaHaven.Services/Interfaces/IEmployeeService.cs b/SeaHaven.Services/Interfaces/IEmployeeService.cs
new file mode 100644
index 0000000..b7be386
--- /dev/null
+++ b/SeaHaven.Services/Interfaces/IEmployeeService.cs
@@ -0,0 +1,17 @@
+using SeaHaven.Services.DTOs;
+
+namespace SeaHaven.Services.Interfaces
+{
+    public interface IEmployeeService
+    {
+        Task<EmployeeDTO?> GetEmployeeByIdAsync(int id);
+        Task<EmployeeDTO?> GetEmployeeByIdWithDetailsAsync(int id);
+        Task<IEnumerable<EmployeeDTO>> GetAllEmployeesAsync();
+        Task<PagedResult<EmployeeDTO>> GetEmployeesPagedAsync(int page, int pageSize, string? search = null);
+        Task<EmployeeDTO> CreateEmployeeAsync(CreateEmployeeDTO dto, string userId);
+        Task<EmployeeDTO> UpdateEmployeeAsync(int id, UpdateEmployeeDTO dto, string userId);
+        Task DeleteEmployeeAsync(int id, string userId);
+        Task<bool> EmployeeExistsAsync(int id);
+        Task<int> GetTotalEmployeeCountAsync();
+    }
+}
diff --git a/SeaHaven.Services/Interfaces/IFollowUpService.cs b/SeaHaven.Services/Interfaces/IFollowUpService.cs
new file mode 100644
index 0000000..ae0b3dd
--- /dev/null
+++ b/SeaHaven.Services/Interfaces/IFollowUpService.cs
@@ -0,0 +1,18 @@
+using SeaHaven.Services.DTOs;
+
+namespace SeaHaven.Services.Interfaces
+{
+    public interface IFollowUpService
+    {
+        Task<FollowUpDTO?> GetFollowUpByIdAsync(int id);
+        Task<FollowUpDTO?> GetFollowUpByIdWithDetailsAsync(int id);
+        Task<IEnumerable<FollowUpDTO>> GetAllFollowUpsAsync();
+        Task<IEnumerable<FollowUpDTO>> GetFollowUpsByWorkOrderIdAsync(int workOrderId);
+        Task<PagedResult<FollowUpDTO>> GetFollowUpsPagedAsync(int page, int pageSize, string? search = null, string? status = null);
+        Task<FollowUpDTO> CreateFollowUpAsync(CreateFollowUpDTO dto, string userId);
+        Task<FollowUpDTO> UpdateFollowUpAsync(int id, UpdateFollowUpDTO dto, string userId);
+        Task DeleteFollowUpAsync(int id, string userId);
+        Task<bool> FollowUpExistsAsync(int id);
+        Task<int> GetTotalFollowUpCountAsync();
+    }
+}
diff --git a/SeaHaven.Services/Interfaces/ILocationService.cs b/SeaHaven.Services/Interfaces/ILocationService.cs
new file mode 100644
index 0000000..7bf9d4e
--- /dev/null
+++ b/SeaHaven.Services/Interfaces/ILocationService.cs
@@ -0,0 +1,18 @@
+using SeaHaven.Services.DTOs;
+
+namespace SeaHaven.Services.Interfaces
+{
+    public interface ILocationService
+    {
+        Task<LocationDTO?> GetLocationByIdAsync(int id);
+        Task<LocationDTO?> GetLocationByIdWithDetailsAsync(int id);
+        Task<IEnumerable<LocationDTO>> GetAllLocationsAsync();
+        Task<IEnumerable<LocationDTO>> GetLocationsByAccountIdAsync(int accountId);
+        Task<PagedResult<LocationDTO>> GetLocationsPagedAsync(int page, int pageSize, string? search = null);
+        Task<LocationDTO> CreateLocationAsync(CreateLocationDTO dto, string userId);
+        Task<LocationDTO> UpdateLocationAsync(int id, UpdateLocationDTO dto, string userId);
+        Task DeleteLocationAsync(int id, string userId);
+        Task<bool> LocationExistsAsync(int id);
+        Task<int> GetTotalLocationCountAsync();
+    }
+}
diff --git a/SeaHaven.Services/Interfaces/IPMScheduleService.cs b/SeaHaven.Services/Interfaces/IPMScheduleService.cs
new file mode 100644
index 0000000..0f12885
--- /dev/null
+++ b/SeaHaven.Services/Interfaces/IPMScheduleService.cs
@@ -0,0 +1,18 @@
+using SeaHaven.Services.DTOs;
+
+namespace SeaHaven.Services.Interfaces
+{
+    public interface IPMScheduleService
+    {
+        Task<PMScheduleDTO?> GetPMScheduleByIdAsync(int id);
+        Task<PMScheduleDTO?> GetPMScheduleByIdWithDetailsAsync(int id);
+        Task<IEnumerable<PMScheduleDTO>> GetAllPMSchedulesAsync();
+        Task<IEnumerable<PMScheduleDTO>> GetPMSchedulesByLocationIdAsync(int locationId);
+        Task<PagedResult<PMScheduleDTO>> GetPMSchedulesPagedAsync(int page, int pageSize, string? search = null);
+        Task<PMScheduleDTO> CreatePMScheduleAsync(CreatePMScheduleDTO dto, string userId);
+        Task<PMScheduleDTO> UpdatePMScheduleAsync(int id, UpdatePMScheduleDTO dto, string userId);
+        Task DeletePMScheduleAsync(int id, string userId);
+        Task<bool> PMScheduleExistsAsync(int id);
+        Task<int> GetTotalPMScheduleCountAsync();
+    }
+}
diff --git a/SeaHaven.Services/Interfaces/IVendorService.cs b/SeaHaven.Services/Interfaces/IVendorService.cs
new file mode 100644
index 0000000..13d996b
--- /dev/null
+++ b/SeaHaven.Services/Interfaces/IVendorService.cs
@@ -0,0 +1,17 @@
+using SeaHaven.Services.DTOs;
+
+namespace SeaHaven.Services.Interfaces
+{
+    public interface IVendorService
+    {
+        Task<VendorDTO?> GetVendorByIdAsync(int id);
+        Task<VendorDTO?> GetVendorByIdWithDetailsAsync(int id);
+        Task<IEnumerable<VendorDTO>> GetAllVendorsAsync();
+        Task<PagedResult<VendorDTO>> GetVendorsPagedAsync(int page, int pageSize, string? search = null);
+        Task<VendorDTO> CreateVendorAsync(CreateVendorDTO dto, string userId);
+        Task<VendorDTO> UpdateVendorAsync(int id, UpdateVendorDTO dto, string userId);
+        Task DeleteVendorAsync(int id, string userId);
+        Task<bool> VendorExistsAsync(int id);
+        Task<int> GetTotalVendorCountAsync();
+    }
+}
diff --git a/SeaHaven.Services/Interfaces/IWorkOrderService.cs b/SeaHaven.Services/Interfaces/IWorkOrderService.cs
new file mode 100644
index 0000000..4a34df3
--- /dev/null
+++ b/SeaHaven.Services/Interfaces/IWorkOrderService.cs
@@ -0,0 +1,18 @@
+using SeaHaven.Services.DTOs;
+
+namespace SeaHaven.Services.Interfaces
+{
+    public interface IWorkOrderService
+    {
+        Task<WorkOrderDTO?> GetWorkOrderByIdAsync(int id);
+        Task<WorkOrderDTO?> GetWorkOrderByIdWithDetailsAsync(int id);
+        Task<IEnumerable<WorkOrderDTO>> GetAllWorkOrdersAsync();
+        Task<PagedResult<WorkOrderDTO>> GetWorkOrdersPagedAsync(int page, int pageSize, string? search = null, string? status = null, string? priority = null);
+        Task<WorkOrderDTO> CreateWorkOrderAsync(CreateWorkOrderDTO dto, string userId);
+        Task<WorkOrderDTO> UpdateWorkOrderAsync(int id, UpdateWorkOrderDTO dto, string userId);
+        Task DeleteWorkOrderAsync(int id, string userId);
+        Task<bool> WorkOrderExistsAsync(int id);
+        Task<string> GenerateNextInternalWONumberAsync();
+        Task<int> GetTotalWorkOrderCountAsync();
+    }
+}
diff --git a/SeaHaven.Services/SeaHaven.Services.csproj b/SeaHaven.Services/SeaHaven.Services.csproj
new file mode 100644
index 0000000..e179849
--- /dev/null
+++ b/SeaHaven.Services/SeaHaven.Services.csproj
@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\SeaHaven.DataServices\SeaHaven.DataServices.csproj" />
+    <ProjectReference Include="..\Data.SeaHavenIndustries\Data.SeaHavenIndustries.csproj" />
+  </ItemGroup>
+
+</Project>
diff --git a/SeaHavenIndustries.sln b/SeaHavenIndustries.sln
index 00b1f6a..5560d76 100644
--- a/SeaHavenIndustries.sln
+++ b/SeaHavenIndustries.sln
@@ -9,6 +9,10 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Data.SeaHavenIndustries", "
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Api.SeaHavenIndustries", "Api.SeaHavenIndustries\Api.SeaHavenIndustries.csproj", "{68A98A85-CD53-44BE-8736-B1CD7A8C5193}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SeaHaven.Services", "SeaHaven.Services\SeaHaven.Services.csproj", "{DFF11D84-FEA1-42D1-99FF-1113133160CA}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SeaHaven.DataServices", "SeaHaven.DataServices\SeaHaven.DataServices.csproj", "{60DF3943-9BC3-4444-8E7A-EEC34DDC7806}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -27,6 +31,14 @@ Global
 		{68A98A85-CD53-44BE-8736-B1CD7A8C5193}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{68A98A85-CD53-44BE-8736-B1CD7A8C5193}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{68A98A85-CD53-44BE-8736-B1CD7A8C5193}.Release|Any CPU.Build.0 = Release|Any CPU
+		{DFF11D84-FEA1-42D1-99FF-1113133160CA}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{DFF11D84-FEA1-42D1-99FF-1113133160CA}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{DFF11D84-FEA1-42D1-99FF-1113133160CA}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{DFF11D84-FEA1-42D1-99FF-1113133160CA}.Release|Any CPU.Build.0 = Release|Any CPU
+		{60DF3943-9BC3-4444-8E7A-EEC34DDC7806}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{60DF3943-9BC3-4444-8E7A-EEC34DDC7806}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{60DF3943-9BC3-4444-8E7A-EEC34DDC7806}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{60DF3943-9BC3-4444-8E7A-EEC34DDC7806}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE