diff --git a/Api.SeaHavenIndustries.Tests/LocationServiceTests.cs b/Api.SeaHavenIndustries.Tests/LocationServiceTests.cs
index 5f3abe2..e6d97bf 100644
--- a/Api.SeaHavenIndustries.Tests/LocationServiceTests.cs
+++ b/Api.SeaHavenIndustries.Tests/LocationServiceTests.cs
@@ -46,11 +46,13 @@ public class LocationServiceTests
             ZipCode = "73301",
             Phone = "555-1000",
             ContactEmail = "wh@example.com",
-            Status = "Active"
+            Status = "Active",
+            AccountId = 9
         }, CancellationToken.None);
 
         var entity = ctx.Locations.Single();
         entity.Name.Should().Be("Warehouse");
+        entity.AccountId.Should().Be(9);
         entity.Title.Should().Be("Main WH");
         entity.Address1.Should().Be("1 Depot Rd");
         entity.City.Should().Be("Austin");
diff --git a/Api.SeaHavenIndustries/Controllers/LocationController.cs b/Api.SeaHavenIndustries/Controllers/LocationController.cs
index b44f58e..dd91983 100644
--- a/Api.SeaHavenIndustries/Controllers/LocationController.cs
+++ b/Api.SeaHavenIndustries/Controllers/LocationController.cs
@@ -51,7 +51,8 @@ namespace Api.SeaHavenIndustries.Controllers
                 Phone = l.PhoneNumber,
                 Contact = (string?)null,
                 ContactEmail = l.Email,
-                Status = l.Status
+                Status = l.Status,
+                AccountId = l.AccountId
             });
 
             var viewModel = new Pagination_DTO
@@ -88,7 +89,8 @@ namespace Api.SeaHavenIndustries.Controllers
                 Phone = location.PhoneNumber,
                 Contact = (string?)null,
                 ContactEmail = location.Email,
-                location.Status
+                location.Status,
+                location.AccountId
             };
 
             return Ok(result);
@@ -175,7 +177,8 @@ namespace Api.SeaHavenIndustries.Controllers
                 ZipCode = model.ZipCode,
                 Phone = model.Phone,
                 ContactEmail = model.ContactEmail,
-                Status = model.Status
+                Status = model.Status,
+                AccountId = model.GetAccountId()
             };
         }
 
@@ -191,7 +194,8 @@ namespace Api.SeaHavenIndustries.Controllers
                 ZipCode = model.ZipCode,
                 Phone = model.Phone,
                 ContactEmail = model.ContactEmail,
-                Status = model.Status
+                Status = model.Status,
+                AccountId = model.GetAccountId()
             };
         }
     }
diff --git a/Api.SeaHavenIndustries/DTOs/Location_DTO.cs b/Api.SeaHavenIndustries/DTOs/Location_DTO.cs
index dcd3c03..c458bf8 100644
--- a/Api.SeaHavenIndustries/DTOs/Location_DTO.cs
+++ b/Api.SeaHavenIndustries/DTOs/Location_DTO.cs
@@ -49,7 +49,7 @@ namespace Api.SeaHavenIndustries.DTOs
                 Contact = null, // Not in database schema
                 ContactEmail = entity.Email,
                 Status = entity.Status,
-                AccountId = null // Not in database schema
+                AccountId = entity.AccountId?.ToString()
             };
         }
 
@@ -68,7 +68,7 @@ namespace Api.SeaHavenIndustries.DTOs
             // Contact field doesn't exist in database schema - ignored
             entity.Email = dto.ContactEmail;
             entity.Status = dto.Status;
-            // AccountId field doesn't exist in database schema - ignored
+            entity.AccountId = dto.GetAccountId();
 
             return entity;
         }
diff --git a/Data.SeaHavenIndustries/Auth/ApplicationDbContext.cs b/Data.SeaHavenIndustries/Auth/ApplicationDbContext.cs
index fb8b588..a5256dc 100644
--- a/Data.SeaHavenIndustries/Auth/ApplicationDbContext.cs
+++ b/Data.SeaHavenIndustries/Auth/ApplicationDbContext.cs
@@ -124,6 +124,13 @@ namespace Data.SeaHavenIndustries
             builder.Entity<Locations>()
                 .Property(l => l.ExternalLocationId)
                 .HasMaxLength(450);
+            builder.Entity<Locations>()
+                .HasOne(l => l.Account)
+                .WithMany()
+                .HasForeignKey(l => l.AccountId)
+                .OnDelete(DeleteBehavior.Restrict);
+            builder.Entity<Locations>()
+                .HasIndex(l => l.AccountId);
             builder.Entity<WorkOrderExternalReceipt>()
                 .HasIndex(r => new { r.Source, r.Kind, r.ExternalId })
                 .IsUnique()
diff --git a/Data.SeaHavenIndustries/Migrations/20260826120000_SH221_LocationAccountScope.cs b/Data.SeaHavenIndustries/Migrations/20260826120000_SH221_LocationAccountScope.cs
new file mode 100644
index 0000000..06d81bd
--- /dev/null
+++ b/Data.SeaHavenIndustries/Migrations/20260826120000_SH221_LocationAccountScope.cs
@@ -0,0 +1,68 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Data.SeaHavenIndustries.Migrations
+{
+    /// <inheritdoc />
+    public partial class SH221_LocationAccountScope : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<int>(
+                name: "AccountId",
+                table: "Locations",
+                type: "int",
+                nullable: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Locations_AccountId",
+                table: "Locations",
+                column: "AccountId");
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_Locations_Accounts_AccountId",
+                table: "Locations",
+                column: "AccountId",
+                principalTable: "Accounts",
+                principalColumn: "Id",
+                onDelete: ReferentialAction.Restrict);
+
+            migrationBuilder.Sql(@"
+;WITH UniqueLocationAccounts AS (
+    SELECT
+        wo.[LocationId] AS [LocationId],
+        MIN(wo.[AccountId]) AS [AccountId]
+    FROM [workOrders] wo
+    WHERE wo.[LocationId] IS NOT NULL
+      AND wo.[AccountId] IS NOT NULL
+    GROUP BY wo.[LocationId]
+    HAVING COUNT(DISTINCT wo.[AccountId]) = 1
+)
+UPDATE loc
+SET loc.[AccountId] = ula.[AccountId]
+FROM [Locations] loc
+INNER JOIN UniqueLocationAccounts ula
+    ON ula.[LocationId] = loc.[Id]
+WHERE loc.[AccountId] IS NULL;
+");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropForeignKey(
+                name: "FK_Locations_Accounts_AccountId",
+                table: "Locations");
+
+            migrationBuilder.DropIndex(
+                name: "IX_Locations_AccountId",
+                table: "Locations");
+
+            migrationBuilder.DropColumn(
+                name: "AccountId",
+                table: "Locations");
+        }
+    }
+}
diff --git a/Data.SeaHavenIndustries/Migrations/ApplicationDbContextModelSnapshot.cs b/Data.SeaHavenIndustries/Migrations/ApplicationDbContextModelSnapshot.cs
index a3051ed..5d86b49 100644
--- a/Data.SeaHavenIndustries/Migrations/ApplicationDbContextModelSnapshot.cs
+++ b/Data.SeaHavenIndustries/Migrations/ApplicationDbContextModelSnapshot.cs
@@ -1486,6 +1486,9 @@ namespace Data.SeaHavenIndustries.Migrations
 
                     SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("Id"));
 
+                    b.Property<int?>("AccountId")
+                        .HasColumnType("int");
+
                     b.Property<string>("Address1")
                         .HasColumnType("nvarchar(max)");
 
@@ -1553,6 +1556,8 @@ namespace Data.SeaHavenIndustries.Migrations
 
                     b.HasKey("Id");
 
+                    b.HasIndex("AccountId");
+
                     b.ToTable("Locations");
                 });
 
@@ -3210,6 +3215,16 @@ namespace Data.SeaHavenIndustries.Migrations
                     b.Navigation("Account");
                 });
 
+            modelBuilder.Entity("Data.SeaHavenIndustries.Locations", b =>
+                {
+                    b.HasOne("Data.SeaHavenIndustries.Accounts", "Account")
+                        .WithMany()
+                        .HasForeignKey("AccountId")
+                        .OnDelete(DeleteBehavior.Restrict);
+
+                    b.Navigation("Account");
+                });
+
             modelBuilder.Entity("Data.SeaHavenIndustries.Assets", b =>
                 {
                     b.HasOne("Data.SeaHavenIndustries.Accounts", "Account")
@@ -3845,6 +3860,8 @@ namespace Data.SeaHavenIndustries.Migrations
 
             modelBuilder.Entity("Data.SeaHavenIndustries.Locations", b =>
                 {
+                    b.Navigation("Account");
+
                     b.Navigation("Templates");
 
                     b.Navigation("workOrders");
diff --git a/Data.SeaHavenIndustries/Models/Locations.cs b/Data.SeaHavenIndustries/Models/Locations.cs
index 9b43e49..f2d9e2e 100644
--- a/Data.SeaHavenIndustries/Models/Locations.cs
+++ b/Data.SeaHavenIndustries/Models/Locations.cs
@@ -1,12 +1,13 @@
-using System;
-using System.ComponentModel.DataAnnotations.Schema;
-using static System.Runtime.InteropServices.JavaScript.JSType;
+using System.ComponentModel.DataAnnotations.Schema;
 
 namespace Data.SeaHavenIndustries
 {
     public class Locations : FullAuditEntity
     {
         public int Id { get; set; }
+        public int? AccountId { get; set; }
+        [ForeignKey(nameof(AccountId))]
+        public Accounts? Account { get; set; }
         public string? Title { get; set; }
         public string? Name { get; set; }
         public string? Latitude { get; set; }
diff --git a/SeaHaven.DataServices/Implementation/LocationDataService.cs b/SeaHaven.DataServices/Implementation/LocationDataService.cs
index 7ccb6b8..48ade48 100644
--- a/SeaHaven.DataServices/Implementation/LocationDataService.cs
+++ b/SeaHaven.DataServices/Implementation/LocationDataService.cs
@@ -31,9 +31,23 @@ namespace SeaHaven.DataServices.Implementation
 
         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();
+            return await _context.Locations
+                .AsNoTracking()
+                .Where(l => l.AccountId == accountId)
+                .ToListAsync();
+        }
+
+        public async Task<(bool Exists, int? AccountId)> GetAccountScopeAsync(
+            int locationId,
+            CancellationToken cancellationToken = default)
+        {
+            var row = await _context.Locations
+                .AsNoTracking()
+                .Where(l => l.Id == locationId)
+                .Select(l => new { l.AccountId })
+                .FirstOrDefaultAsync(cancellationToken);
+
+            return row == null ? (false, null) : (true, row.AccountId);
         }
 
         public async Task<(IEnumerable<Locations> Items, int TotalCount)> GetPagedAsync(
diff --git a/SeaHaven.DataServices/Interfaces/ILocationDataService.cs b/SeaHaven.DataServices/Interfaces/ILocationDataService.cs
index a88609a..1bba950 100644
--- a/SeaHaven.DataServices/Interfaces/ILocationDataService.cs
+++ b/SeaHaven.DataServices/Interfaces/ILocationDataService.cs
@@ -19,6 +19,13 @@ namespace SeaHaven.DataServices.Interfaces
 
         Task<IReadOnlyList<SiteOptionRow>> GetSiteOptionsAsync(string? search = null);
 
+        /// <summary>
+        /// Exists is false when the row is missing. AccountId is null when the site has no account.
+        /// </summary>
+        Task<(bool Exists, int? AccountId)> GetAccountScopeAsync(
+            int locationId,
+            CancellationToken cancellationToken = default);
+
         Task<Locations> AddAsync(Locations location);
         Task UpdateAsync(Locations location);
         Task DeleteAsync(int id);
diff --git a/SeaHaven.Services/DTOs/LocationDTOs.cs b/SeaHaven.Services/DTOs/LocationDTOs.cs
index 3a6edcd..fe694f8 100644
--- a/SeaHaven.Services/DTOs/LocationDTOs.cs
+++ b/SeaHaven.Services/DTOs/LocationDTOs.cs
@@ -13,6 +13,7 @@ namespace SeaHaven.Services.DTOs
         public string? PhoneNumber { get; set; }
         public string? Email { get; set; }
         public string? Status { get; set; }
+        public int? AccountId { get; set; }
         public DateTime? CreatedDate { get; set; }
         public string? CreatedBy { get; set; }
     }
@@ -48,6 +49,7 @@ namespace SeaHaven.Services.DTOs
         public string? Phone { get; set; }
         public string? ContactEmail { get; set; }
         public string? Status { get; set; }
+        public int? AccountId { get; set; }
     }
 
     public class LocationUpdateRequestDTO
@@ -61,6 +63,7 @@ namespace SeaHaven.Services.DTOs
         public string? Phone { get; set; }
         public string? ContactEmail { get; set; }
         public string? Status { get; set; }
+        public int? AccountId { get; set; }
     }
 
     public class SiteOptionDTO
diff --git a/SeaHaven.Services/DTOs/WorkOrderBoardRequestDTOs.cs b/SeaHaven.Services/DTOs/WorkOrderBoardRequestDTOs.cs
index d9718ff..593415e 100644
--- a/SeaHaven.Services/DTOs/WorkOrderBoardRequestDTOs.cs
+++ b/SeaHaven.Services/DTOs/WorkOrderBoardRequestDTOs.cs
@@ -21,8 +21,8 @@ namespace SeaHaven.Services.DTOs
         public bool? IsAddOn { get; set; }
         public string? SiteCode { get; set; }
         /// <summary>
-        /// Optional CRM customer name. Required when the caller is org-wide (no account_id)
-        /// so AccountId can be resolved server-side.
+        /// Optional display customer name. Ignored when stamping AccountId
+        /// (board create resolves from Location.AccountId).
         /// </summary>
         public string? Customer { get; set; }
         public string? Description { get; set; }
diff --git a/SeaHaven.Services/Implementation/LocationService.cs b/SeaHaven.Services/Implementation/LocationService.cs
index da98b66..2a8fbcf 100644
--- a/SeaHaven.Services/Implementation/LocationService.cs
+++ b/SeaHaven.Services/Implementation/LocationService.cs
@@ -94,6 +94,7 @@ namespace SeaHaven.Services.Implementation
                 City = dto.City,
                 State = dto.State,
                 Zip = dto.Zipcode,
+                AccountId = dto.AccountId,
                 CreatedDate = DateTime.UtcNow,
                 createdby = userId
             };
@@ -121,6 +122,7 @@ namespace SeaHaven.Services.Implementation
             if (dto.City != null) location.City = dto.City;
             if (dto.State != null) location.State = dto.State;
             if (dto.Zipcode != null) location.Zip = dto.Zipcode;
+            if (dto.AccountId.HasValue) location.AccountId = dto.AccountId;
 
             location.LastModificationTime = DateTime.UtcNow;
             if (int.TryParse(userId, out int userIdInt))
@@ -187,7 +189,8 @@ namespace SeaHaven.Services.Implementation
                 Zip = request.ZipCode,
                 PhoneNumber = request.Phone,
                 Email = request.ContactEmail,
-                Status = request.Status
+                Status = request.Status,
+                AccountId = request.AccountId
             };
 
             await _locationDataService.AddAsync(location, cancellationToken);
@@ -208,6 +211,7 @@ namespace SeaHaven.Services.Implementation
             location.PhoneNumber = request.Phone;
             location.Email = request.ContactEmail;
             location.Status = request.Status;
+            location.AccountId = request.AccountId;
 
             await _locationDataService.UpdateAsync(location, cancellationToken);
         }
@@ -233,6 +237,7 @@ namespace SeaHaven.Services.Implementation
                 PhoneNumber = location.PhoneNumber,
                 Email = location.Email,
                 Status = location.Status,
+                AccountId = location.AccountId,
                 CreatedDate = location.CreatedDate,
                 CreatedBy = location.createdby
             };
diff --git a/SeaHaven.Services/Implementation/WorkOrderAccountResolver.cs b/SeaHaven.Services/Implementation/WorkOrderAccountResolver.cs
index d6a9419..c09d2f7 100644
--- a/SeaHaven.Services/Implementation/WorkOrderAccountResolver.cs
+++ b/SeaHaven.Services/Implementation/WorkOrderAccountResolver.cs
@@ -9,10 +9,12 @@ namespace SeaHaven.Services.Implementation
     public class WorkOrderAccountResolver : IWorkOrderAccountResolver
     {
         private readonly IAccountDataService _accounts;
+        private readonly ILocationDataService _locations;
 
-        public WorkOrderAccountResolver(IAccountDataService accounts)
+        public WorkOrderAccountResolver(IAccountDataService accounts, ILocationDataService locations)
         {
             _accounts = accounts;
+            _locations = locations;
         }
 
         public int? ResolveAccountFilter(ClaimsPrincipal user)
@@ -47,6 +49,55 @@ namespace SeaHaven.Services.Implementation
             }
         }
 
+        public async Task<int> ResolveForBoardCreateAsync(
+            ClaimsPrincipal user,
+            int? locationId,
+            CancellationToken cancellationToken = default)
+        {
+            if (locationId is not int id || id <= 0)
+            {
+                throw new WorkOrderBoardValidationException(
+                    "InvalidValue",
+                    "locationId is required.");
+            }
+
+            var (exists, locationAccountId) = await _locations.GetAccountScopeAsync(id, cancellationToken);
+            if (!exists)
+            {
+                throw new WorkOrderBoardValidationException(
+                    "NotFound",
+                    "Location was not found.");
+            }
+
+            if (locationAccountId is not int resolvedAccountId)
+            {
+                throw new WorkOrderBoardValidationException(
+                    "AccountUnresolved",
+                    "Work order account could not be resolved from location.");
+            }
+
+            switch (WorkOrderMediaAuthorization.ResolveMediaScope(user))
+            {
+                case MediaAccountScope.Account account:
+                    if (account.AccountId != resolvedAccountId)
+                    {
+                        throw new WorkOrderBoardValidationException(
+                            "Forbidden",
+                            "You are not allowed to create a work order for this location.");
+                    }
+
+                    return account.AccountId;
+
+                case MediaAccountScope.OrgWide:
+                    return resolvedAccountId;
+
+                default:
+                    throw new WorkOrderBoardValidationException(
+                        "Forbidden",
+                        "You are not allowed to create work orders without account scope.");
+            }
+        }
+
         public Task<int> ResolveForUnauthenticatedCreateAsync(
             string? customer,
             CancellationToken cancellationToken = default)
diff --git a/SeaHaven.Services/Implementation/WorkOrderBoardCreateService.cs b/SeaHaven.Services/Implementation/WorkOrderBoardCreateService.cs
index f644f6e..c584b75 100644
--- a/SeaHaven.Services/Implementation/WorkOrderBoardCreateService.cs
+++ b/SeaHaven.Services/Implementation/WorkOrderBoardCreateService.cs
@@ -46,9 +46,9 @@ namespace SeaHaven.Services.Implementation
             if (!validationResult.IsValid)
                 throw new ValidationException(validationResult.Errors);
 
-            var accountId = await _accountResolver.ResolveForAuthenticatedCreateAsync(
+            var accountId = await _accountResolver.ResolveForBoardCreateAsync(
                 user,
-                request.Customer,
+                request.LocationId,
                 CancellationToken.None);
 
             var woNumber = await ResolveWoNumberAsync(request.WoNumber);
diff --git a/SeaHaven.Services/Interfaces/IWorkOrderAccountResolver.cs b/SeaHaven.Services/Interfaces/IWorkOrderAccountResolver.cs
index 8fd209c..6aac4d1 100644
--- a/SeaHaven.Services/Interfaces/IWorkOrderAccountResolver.cs
+++ b/SeaHaven.Services/Interfaces/IWorkOrderAccountResolver.cs
@@ -4,7 +4,7 @@ namespace SeaHaven.Services.Interfaces
 {
     /// <summary>
     /// Server-derived work-order account scope (SH-221): claims for authenticated callers,
-    /// unique Accounts.Name ↔ Customer for org-wide / unauthenticated creates.
+    /// Location.AccountId for board create, unique Accounts.Name ↔ Customer for ingest/webhook.
     /// </summary>
     public interface IWorkOrderAccountResolver
     {
@@ -17,12 +17,23 @@ namespace SeaHaven.Services.Interfaces
         /// <summary>
         /// Authenticated create: claim account_id, or org-wide Customer unique match.
         /// Missing scope → Forbidden. Unresolvable org-wide Customer → AccountUnresolved.
+        /// Used by legacy AddWorkorder — not board create.
         /// </summary>
         Task<int> ResolveForAuthenticatedCreateAsync(
             ClaimsPrincipal user,
             string? customer,
             CancellationToken cancellationToken = default);
 
+        /// <summary>
+        /// Board create: stamp from JWT account_id or Location.AccountId. Never trusts body customer/accountId.
+        /// Missing locationId → InvalidValue. Missing location → NotFound. Null Location.AccountId → AccountUnresolved.
+        /// Scoped location mismatch → Forbidden.
+        /// </summary>
+        Task<int> ResolveForBoardCreateAsync(
+            ClaimsPrincipal user,
+            int? locationId,
+            CancellationToken cancellationToken = default);
+
         /// <summary>
         /// Ingest/webhook/sync create: unique Customer → Accounts.Id or AccountUnresolved.
         /// </summary>
diff --git a/SeaHaven.Services/Validation/WorkOrderBoardCreateValidation.cs b/SeaHaven.Services/Validation/WorkOrderBoardCreateValidation.cs
index 2ed2868..7eb2364 100644
--- a/SeaHaven.Services/Validation/WorkOrderBoardCreateValidation.cs
+++ b/SeaHaven.Services/Validation/WorkOrderBoardCreateValidation.cs
@@ -62,8 +62,8 @@ namespace SeaHaven.Services.Validation
                 .When(x => !string.IsNullOrEmpty(x.VendorNotes));
 
             RuleFor(x => x.LocationId)
-                .GreaterThan(0)
-                .When(x => x.LocationId.HasValue);
+                .NotNull().WithMessage("locationId is required.")
+                .GreaterThan(0).WithMessage("locationId is required.");
 
             RuleFor(x => x.VendorId)
                 .GreaterThan(0)
diff --git a/SeaHavenIndustries.Tests/WorkOrderAccountScopeTests.cs b/SeaHavenIndustries.Tests/WorkOrderAccountScopeTests.cs
index 4b75111..85086b2 100644
--- a/SeaHavenIndustries.Tests/WorkOrderAccountScopeTests.cs
+++ b/SeaHavenIndustries.Tests/WorkOrderAccountScopeTests.cs
@@ -1,4 +1,5 @@
 using System.Security.Claims;
+using FluentValidation;
 using Data.SeaHavenIndustries;
 using Data.SeaHavenIndustries.Enums;
 using Microsoft.EntityFrameworkCore;
@@ -22,54 +23,57 @@ public class WorkOrderAccountScopeTests
         return new ApplicationDbContext(options);
     }
 
-    [Fact]
-    public async Task BoardCreate_WithAccountClaim_StampsAccountId()
+    private static WorkOrderBoardCreateService CreateBoardCreate(ApplicationDbContext context)
     {
-        await using var context = CreateContext();
-        await WorkOrderAccountTestHelpers.EnsureAccountAsync(context, 7, "Scoped Co");
-
         var resolver = WorkOrderAccountTestHelpers.Resolver(context);
         var boardData = new WorkOrderBoardDataService(context);
         var mutationData = new WorkOrderBoardMutationDataService(context);
         var boardService = new WorkOrderBoardService(boardData, resolver);
         var fieldLocks = new WorkOrderFieldLockService(new WorkOrderFieldLockDataService(context));
         var audit = new WorkOrderAuditService(new WorkOrderAuditDataService(context), fieldLocks);
-        var create = new WorkOrderBoardCreateService(
+        return new WorkOrderBoardCreateService(
             boardData, mutationData, boardService, audit, new WorkOrderBoardCreateValidation(), resolver);
+    }
 
+    [Fact]
+    public async Task BoardCreate_WithAccountClaim_StampsAccountId()
+    {
+        await using var context = CreateContext();
+        await WorkOrderAccountTestHelpers.EnsureAccountAsync(context, 7, "Scoped Co");
+        await WorkOrderAccountTestHelpers.EnsureLocationAsync(context, id: 11, accountId: 7);
+
+        var create = CreateBoardCreate(context);
         var user = WorkOrderAccountTestHelpers.AccountUser("actor-1", 7, "Dispatcher");
         var row = await create.CreateAsync(
             new WorkOrderBoardCreateRequestDto
             {
                 WorkOrderType = WorkOrderType.PM,
-                SiteCode = "BK5"
+                SiteCode = "BK5",
+                LocationId = 11
             },
             user,
             "actor-1");
 
         var wo = await context.workOrders.AsNoTracking().SingleAsync(w => w.Id == row.Id);
         Assert.Equal(7, wo.AccountId);
+        Assert.Equal(11, wo.LocationId);
     }
 
     [Fact]
     public async Task BoardCreate_MissingScope_ThrowsForbidden()
     {
         await using var context = CreateContext();
-        var resolver = WorkOrderAccountTestHelpers.Resolver(context);
-        var boardData = new WorkOrderBoardDataService(context);
-        var mutationData = new WorkOrderBoardMutationDataService(context);
-        var boardService = new WorkOrderBoardService(boardData, resolver);
-        var fieldLocks = new WorkOrderFieldLockService(new WorkOrderFieldLockDataService(context));
-        var audit = new WorkOrderAuditService(new WorkOrderAuditDataService(context), fieldLocks);
-        var create = new WorkOrderBoardCreateService(
-            boardData, mutationData, boardService, audit, new WorkOrderBoardCreateValidation(), resolver);
+        await WorkOrderAccountTestHelpers.EnsureAccountAsync(context, 1, "A");
+        await WorkOrderAccountTestHelpers.EnsureLocationAsync(context, id: 11, accountId: 1);
+        var create = CreateBoardCreate(context);
 
         var ex = await Assert.ThrowsAsync<WorkOrderBoardValidationException>(() =>
             create.CreateAsync(
                 new WorkOrderBoardCreateRequestDto
                 {
                     WorkOrderType = WorkOrderType.PM,
-                    SiteCode = "BK5"
+                    SiteCode = "BK5",
+                    LocationId = 11
                 },
                 WorkOrderAccountTestHelpers.MissingScope(),
                 "actor-1"));
@@ -79,49 +83,80 @@ public class WorkOrderAccountScopeTests
     }
 
     [Fact]
-    public async Task BoardCreate_OrgWide_WithUniqueCustomer_StampsAccountId()
+    public async Task BoardCreate_OrgWide_WithLocationAccount_StampsAccountId()
     {
         await using var context = CreateContext();
         await WorkOrderAccountTestHelpers.EnsureAccountAsync(context, 3, "Unique Customer");
+        await WorkOrderAccountTestHelpers.EnsureLocationAsync(context, id: 22, accountId: 3, name: "DAL");
 
-        var resolver = WorkOrderAccountTestHelpers.Resolver(context);
-        var boardData = new WorkOrderBoardDataService(context);
-        var mutationData = new WorkOrderBoardMutationDataService(context);
-        var boardService = new WorkOrderBoardService(boardData, resolver);
-        var fieldLocks = new WorkOrderFieldLockService(new WorkOrderFieldLockDataService(context));
-        var audit = new WorkOrderAuditService(new WorkOrderAuditDataService(context), fieldLocks);
-        var create = new WorkOrderBoardCreateService(
-            boardData, mutationData, boardService, audit, new WorkOrderBoardCreateValidation(), resolver);
-
+        var create = CreateBoardCreate(context);
         var row = await create.CreateAsync(
             new WorkOrderBoardCreateRequestDto
             {
                 WorkOrderType = WorkOrderType.PO,
                 SiteCode = "DAL",
-                Customer = "Unique Customer"
+                LocationId = 22,
+                Customer = "Ignored Client Customer"
             },
             WorkOrderAccountTestHelpers.OrgWideAdmin(),
             "admin-1");
 
         var wo = await context.workOrders.AsNoTracking().SingleAsync(w => w.Id == row.Id);
         Assert.Equal(3, wo.AccountId);
-        Assert.Equal("Unique Customer", wo.Customer);
+        Assert.Equal(22, wo.LocationId);
+        Assert.Equal("Ignored Client Customer", wo.Customer);
     }
 
     [Fact]
-    public async Task BoardCreate_OrgWide_UnresolvedCustomer_ThrowsAccountUnresolved()
+    public async Task BoardCreate_OrgWide_LocationWithoutAccount_ThrowsAccountUnresolved()
     {
         await using var context = CreateContext();
-        var resolver = WorkOrderAccountTestHelpers.Resolver(context);
-        var boardData = new WorkOrderBoardDataService(context);
-        var mutationData = new WorkOrderBoardMutationDataService(context);
-        var boardService = new WorkOrderBoardService(boardData, resolver);
-        var fieldLocks = new WorkOrderFieldLockService(new WorkOrderFieldLockDataService(context));
-        var audit = new WorkOrderAuditService(new WorkOrderAuditDataService(context), fieldLocks);
-        var create = new WorkOrderBoardCreateService(
-            boardData, mutationData, boardService, audit, new WorkOrderBoardCreateValidation(), resolver);
+        await WorkOrderAccountTestHelpers.EnsureLocationAsync(context, id: 33, accountId: null);
+        var create = CreateBoardCreate(context);
 
         var ex = await Assert.ThrowsAsync<WorkOrderBoardValidationException>(() =>
+            create.CreateAsync(
+                new WorkOrderBoardCreateRequestDto
+                {
+                    WorkOrderType = WorkOrderType.PM,
+                    SiteCode = "BK5",
+                    LocationId = 33
+                },
+                WorkOrderAccountTestHelpers.OrgWideAdmin(),
+                "admin-1"));
+
+        Assert.Equal("AccountUnresolved", ex.Code);
+        Assert.Empty(context.workOrders);
+    }
+
+    [Fact]
+    public async Task BoardCreate_OrgWide_MissingLocation_ThrowsNotFound()
+    {
+        await using var context = CreateContext();
+        var create = CreateBoardCreate(context);
+
+        var ex = await Assert.ThrowsAsync<WorkOrderBoardValidationException>(() =>
+            create.CreateAsync(
+                new WorkOrderBoardCreateRequestDto
+                {
+                    WorkOrderType = WorkOrderType.PM,
+                    SiteCode = "BK5",
+                    LocationId = 404
+                },
+                WorkOrderAccountTestHelpers.OrgWideAdmin(),
+                "admin-1"));
+
+        Assert.Equal("NotFound", ex.Code);
+        Assert.Empty(context.workOrders);
+    }
+
+    [Fact]
+    public async Task BoardCreate_MissingLocationId_ThrowsValidation()
+    {
+        await using var context = CreateContext();
+        var create = CreateBoardCreate(context);
+
+        await Assert.ThrowsAsync<ValidationException>(() =>
             create.CreateAsync(
                 new WorkOrderBoardCreateRequestDto
                 {
@@ -131,10 +166,56 @@ public class WorkOrderAccountScopeTests
                 WorkOrderAccountTestHelpers.OrgWideAdmin(),
                 "admin-1"));
 
-        Assert.Equal("AccountUnresolved", ex.Code);
         Assert.Empty(context.workOrders);
     }
 
+    [Fact]
+    public async Task BoardCreate_Scoped_LocationOfOtherAccount_ThrowsForbidden()
+    {
+        await using var context = CreateContext();
+        await WorkOrderAccountTestHelpers.EnsureAccountAsync(context, 1, "A");
+        await WorkOrderAccountTestHelpers.EnsureAccountAsync(context, 2, "B");
+        await WorkOrderAccountTestHelpers.EnsureLocationAsync(context, id: 50, accountId: 2);
+        var create = CreateBoardCreate(context);
+
+        var ex = await Assert.ThrowsAsync<WorkOrderBoardValidationException>(() =>
+            create.CreateAsync(
+                new WorkOrderBoardCreateRequestDto
+                {
+                    WorkOrderType = WorkOrderType.PM,
+                    SiteCode = "BK5",
+                    LocationId = 50
+                },
+                WorkOrderAccountTestHelpers.AccountUser("disp-1", 1, "Dispatcher"),
+                "disp-1"));
+
+        Assert.Equal("Forbidden", ex.Code);
+        Assert.Empty(context.workOrders);
+    }
+
+    [Fact]
+    public async Task BoardCreate_OrgWide_ServiceOmitted_Succeeds()
+    {
+        await using var context = CreateContext();
+        await WorkOrderAccountTestHelpers.EnsureAccountAsync(context, 3, "Org");
+        await WorkOrderAccountTestHelpers.EnsureLocationAsync(context, id: 60, accountId: 3);
+        var create = CreateBoardCreate(context);
+
+        var row = await create.CreateAsync(
+            new WorkOrderBoardCreateRequestDto
+            {
+                WorkOrderType = WorkOrderType.PM,
+                SiteCode = "BK5",
+                LocationId = 60
+            },
+            WorkOrderAccountTestHelpers.OrgWideAdmin(),
+            "admin-1");
+
+        Assert.Null(row.Pm);
+        var wo = await context.workOrders.AsNoTracking().SingleAsync(w => w.Id == row.Id);
+        Assert.Equal(3, wo.AccountId);
+    }
+
     [Fact]
     public async Task Board_ScopedUser_HidesOtherAccountAndNullAccountRows()
     {
diff --git a/SeaHavenIndustries.Tests/WorkOrderAccountTestHelpers.cs b/SeaHavenIndustries.Tests/WorkOrderAccountTestHelpers.cs
index 471c0ea..cb7c9f9 100644
--- a/SeaHavenIndustries.Tests/WorkOrderAccountTestHelpers.cs
+++ b/SeaHavenIndustries.Tests/WorkOrderAccountTestHelpers.cs
@@ -11,7 +11,9 @@ namespace SeaHavenIndustries.Tests;
 internal static class WorkOrderAccountTestHelpers
 {
     public static IWorkOrderAccountResolver Resolver(ApplicationDbContext context)
-        => new WorkOrderAccountResolver(new AccountDataService(context));
+        => new WorkOrderAccountResolver(
+            new AccountDataService(context),
+            new LocationDataService(context));
 
     public static ClaimsPrincipal AccountUser(
         string userId = "actor-1",
@@ -65,4 +67,53 @@ internal static class WorkOrderAccountTestHelpers
         });
         await context.SaveChangesAsync();
     }
+
+    public static async Task EnsureLocationAsync(
+        ApplicationDbContext context,
+        int id = 1,
+        int? accountId = 1,
+        string name = "BK5")
+    {
+        if (await context.Locations.AnyAsync(l => l.Id == id))
+            return;
+
+        context.Locations.Add(new Locations
+        {
+            Id = id,
+            Name = name,
+            AccountId = accountId
+        });
+        await context.SaveChangesAsync();
+    }
+
+    public static void SeedBoardCreateScope(
+        ApplicationDbContext context,
+        int accountId = 1,
+        int locationId = 1,
+        string accountName = "Acme Corp")
+    {
+        if (!context.Accounts.Local.Any(a => a.Id == accountId)
+            && !context.Accounts.Any(a => a.Id == accountId))
+        {
+            context.Accounts.Add(new Accounts
+            {
+                Id = accountId,
+                Name = accountName,
+                IsDeleted = false
+            });
+        }
+
+        if (!context.Locations.Local.Any(l => l.Id == locationId)
+            && !context.Locations.Any(l => l.Id == locationId))
+        {
+            context.Locations.Add(new Locations
+            {
+                Id = locationId,
+                Name = "BK5",
+                AccountId = accountId
+            });
+        }
+
+        context.SaveChanges();
+    }
 }
diff --git a/SeaHavenIndustries.Tests/WorkOrderBoardCreateRelationalTests.cs b/SeaHavenIndustries.Tests/WorkOrderBoardCreateRelationalTests.cs
index 29be2eb..fe1aee0 100644
--- a/SeaHavenIndustries.Tests/WorkOrderBoardCreateRelationalTests.cs
+++ b/SeaHavenIndustries.Tests/WorkOrderBoardCreateRelationalTests.cs
@@ -35,6 +35,7 @@ public class WorkOrderBoardCreateRelationalTests
         });
         await context.SaveChangesAsync();
         await WorkOrderAccountTestHelpers.EnsureAccountAsync(context);
+        await WorkOrderAccountTestHelpers.EnsureLocationAsync(context);
 
         var boardData = new WorkOrderBoardDataService(context);
         var mutationData = new WorkOrderBoardMutationDataService(context);
@@ -54,6 +55,7 @@ public class WorkOrderBoardCreateRelationalTests
         {
             WorkOrderType = WorkOrderType.PM,
             SiteCode = "BK5",
+            LocationId = 1,
             Description = "Relational create"
         }, WorkOrderAccountTestHelpers.AccountUser(actorId), actorId);
 
@@ -95,6 +97,7 @@ public class WorkOrderBoardCreateRelationalTests
         });
         await context.SaveChangesAsync();
         await WorkOrderAccountTestHelpers.EnsureAccountAsync(context);
+        await WorkOrderAccountTestHelpers.EnsureLocationAsync(context);
 
         var boardData = new WorkOrderBoardDataService(context);
         var mutationData = new WorkOrderBoardMutationDataService(context);
@@ -115,6 +118,7 @@ public class WorkOrderBoardCreateRelationalTests
             {
                 WorkOrderType = WorkOrderType.PM,
                 SiteCode = "BK5",
+                LocationId = 1,
                 Description = "Should roll back",
                 PocContactId = 999_999
             }, WorkOrderAccountTestHelpers.AccountUser(actorId), actorId));
diff --git a/SeaHavenIndustries.Tests/WorkOrderBoardCreateServiceTests.cs b/SeaHavenIndustries.Tests/WorkOrderBoardCreateServiceTests.cs
index 53f4f84..ef58783 100644
--- a/SeaHavenIndustries.Tests/WorkOrderBoardCreateServiceTests.cs
+++ b/SeaHavenIndustries.Tests/WorkOrderBoardCreateServiceTests.cs
@@ -19,6 +19,7 @@ public class WorkOrderBoardCreateServiceTests
             .UseInMemoryDatabase(Guid.NewGuid().ToString())
             .Options;
         var context = new ApplicationDbContext(options);
+        WorkOrderAccountTestHelpers.SeedBoardCreateScope(context);
         var boardData = new WorkOrderBoardDataService(context);
         var mutationData = new WorkOrderBoardMutationDataService(context);
         var resolver = WorkOrderAccountTestHelpers.Resolver(context);
@@ -38,7 +39,8 @@ public class WorkOrderBoardCreateServiceTests
         var result = await service.CreateAsync(new WorkOrderBoardCreateRequestDto
         {
             WorkOrderType = WorkOrderType.PM,
-            SiteCode = "BK5"
+            SiteCode = "BK5",
+            LocationId = 1
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
 
         Assert.Equal(LifecycleStatus.Incomplete, result.LifecycleStatus);
@@ -61,7 +63,8 @@ public class WorkOrderBoardCreateServiceTests
         var result = await service.CreateAsync(new WorkOrderBoardCreateRequestDto
         {
             WorkOrderType = WorkOrderType.PM,
-            SiteCode = "BK5"
+            SiteCode = "BK5",
+            LocationId = 1
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
 
         Assert.Equal("SH00002", result.WoNumber);
@@ -77,7 +80,8 @@ public class WorkOrderBoardCreateServiceTests
         {
             WoNumber = "12345",
             WorkOrderType = WorkOrderType.PO,
-            SiteCode = "DAL"
+            SiteCode = "DAL",
+            LocationId = 1
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
 
         Assert.Equal("00000012345", result.WoNumber);
@@ -95,7 +99,8 @@ public class WorkOrderBoardCreateServiceTests
             {
                 WoNumber = "99999",
                 WorkOrderType = WorkOrderType.PM,
-                SiteCode = "BK5"
+                SiteCode = "BK5",
+                LocationId = 1
             }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1"));
 
         Assert.Equal("DuplicateWoNumber", ex.Code);
@@ -110,6 +115,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.PM,
             SiteCode = "BK5",
+            LocationId = 1,
             AssignTo = "dispatcher-1",
             ScheduledDate = new DateTime(2026, 6, 25)
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
@@ -127,6 +133,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.PM,
             SiteCode = "BK5",
+            LocationId = 1,
             ScheduleWeekOnly = true,
             TargetWeek = new DateOnly(2026, 6, 22)
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
@@ -145,6 +152,7 @@ public class WorkOrderBoardCreateServiceTests
             {
                 WorkOrderType = WorkOrderType.PM,
                 SiteCode = "BK5",
+                LocationId = 1,
                 ScheduleWeekOnly = true
             }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1"));
     }
@@ -160,6 +168,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.PM,
             SiteCode = "BK5",
+            LocationId = 1,
             VendorId = 5,
             ApptDate = new DateTime(2026, 6, 26)
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
@@ -177,6 +186,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.PM,
             SiteCode = "BK5",
+            LocationId = 1,
             Description = "Test WO"
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
 
@@ -195,7 +205,8 @@ public class WorkOrderBoardCreateServiceTests
         var result = await service.CreateAsync(new WorkOrderBoardCreateRequestDto
         {
             WorkOrderType = WorkOrderType.PM,
-            SiteCode = "BK5"
+            SiteCode = "BK5",
+            LocationId = 1
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
 
         var logs = await context.WorkOrderAuditLogs.ToListAsync();
@@ -214,6 +225,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.PM,
             SiteCode = "BK5",
+            LocationId = 1,
             PrimaryService = "HVAC PM",
             ExtraServices = new List<string> { "Filter change", "Coil clean", "Filter change" },
             ServiceNotes = "Unit on roof"
@@ -241,6 +253,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.Reactive,
             SiteCode = "CHI",
+            LocationId = 1,
             Trade = "Legacy Trade",
             PrimaryService = "Plumbing"
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
@@ -258,6 +271,7 @@ public class WorkOrderBoardCreateServiceTests
             {
                 WorkOrderType = WorkOrderType.PM,
                 SiteCode = "BK5",
+                LocationId = 1,
                 ExtraServices = new List<string> { "Filter change" }
             }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1"));
     }
@@ -271,6 +285,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.Reactive,
             SiteCode = "BK5",
+            LocationId = 1,
             PocName = "Jane Site Lead",
             PocPhone = "+1 555-0100",
             PocNotes = "Call 30 min before"
@@ -294,6 +309,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.PM,
             SiteCode = "BK5",
+            LocationId = 1,
             TechPhone = "+1 555-0199",
             VendorNotes = "Gate code 4421"
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
@@ -317,6 +333,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.PM,
             SiteCode = "BK5",
+            LocationId = 1,
             VendorId = 55,
             ApptDate = new DateTime(2026, 7, 18),
             TechPhone = "+1 555-0199",
@@ -343,6 +360,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.PM,
             SiteCode = "BK5",
+            LocationId = 1,
             Trade = "HVAC",
             Description = "pmNote\nPOC: Jane · +1 555\nVendor notes: gate"
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
@@ -368,6 +386,7 @@ public class WorkOrderBoardCreateServiceTests
             {
                 WorkOrderType = WorkOrderType.PM,
                 SiteCode = "BK5",
+                LocationId = 1,
                 VendorId = 999
             }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1"));
 
@@ -384,6 +403,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.PM,
             SiteCode = "BK5",
+            LocationId = 1,
             ScheduledDate = new DateTime(2026, 6, 24),
             IsAddOn = false
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
@@ -405,6 +425,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.Reactive,
             SiteCode = "BK5",
+            LocationId = 1,
             ScheduledDate = new DateTime(2099, 3, 10),
             IsAddOn = true
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
@@ -424,6 +445,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.PM,
             SiteCode = "BK5",
+            LocationId = 1,
             IsAddOn = true
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
 
@@ -441,6 +463,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.PM,
             SiteCode = "BK5",
+            LocationId = 1,
             AvetaRequired = true
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
 
@@ -460,7 +483,8 @@ public class WorkOrderBoardCreateServiceTests
         var result = await service.CreateAsync(new WorkOrderBoardCreateRequestDto
         {
             WorkOrderType = WorkOrderType.PM,
-            SiteCode = "BK5"
+            SiteCode = "BK5",
+            LocationId = 1
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
 
         Assert.False(result.AvetaRequired);
@@ -480,7 +504,8 @@ public class WorkOrderBoardCreateServiceTests
             service.CreateAsync(new WorkOrderBoardCreateRequestDto
             {
                 WorkOrderType = WorkOrderType.AddOn,
-                SiteCode = "BK5"
+                SiteCode = "BK5",
+                LocationId = 1
             }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1"));
 
         Assert.Contains(ex.Errors, e => e.PropertyName == "WorkOrderType");
@@ -495,6 +520,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.Reactive,
             SiteCode = "BK5",
+            LocationId = 1,
             PocName = "Primary Lead",
             AdditionalContacts = new List<WorkOrderAdditionalContactDto>
             {
@@ -525,6 +551,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.PM,
             SiteCode = "BK5",
+            LocationId = 1,
             AdditionalContacts = new List<WorkOrderAdditionalContactDto>()
         }, WorkOrderAccountTestHelpers.AccountUser(), "actor-1");
 
@@ -540,6 +567,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.Reactive,
             SiteCode = "BK5",
+            LocationId = 1,
             AdditionalContacts = new List<WorkOrderAdditionalContactDto>
             {
                 new("", "", null),
@@ -565,6 +593,7 @@ public class WorkOrderBoardCreateServiceTests
             {
                 WorkOrderType = WorkOrderType.PM,
                 SiteCode = "BK5",
+                LocationId = 1,
                 AdditionalContacts = new List<WorkOrderAdditionalContactDto>
                 {
                     new("Backup Lead", "", null)
@@ -584,6 +613,7 @@ public class WorkOrderBoardCreateServiceTests
             {
                 WorkOrderType = WorkOrderType.PM,
                 SiteCode = "BK5",
+                LocationId = 1,
                 AdditionalContacts = new List<WorkOrderAdditionalContactDto>
                 {
                     new("", "+1 555-0101", null)
@@ -599,6 +629,7 @@ public class WorkOrderBoardCreateServiceTests
         {
             WorkOrderType = WorkOrderType.Reactive,
             SiteCode = "BK5",
+            LocationId = 1,
             AdditionalContacts = new List<WorkOrderAdditionalContactDto>
             {
                 new("Backup Lead", "+1 555-0101", "After hours"),
diff --git a/SeaHavenIndustries.Tests/WorkOrderBoardCreateSyncLockTests.cs b/SeaHavenIndustries.Tests/WorkOrderBoardCreateSyncLockTests.cs
index b1e60f3..62ff194 100644
--- a/SeaHavenIndustries.Tests/WorkOrderBoardCreateSyncLockTests.cs
+++ b/SeaHavenIndustries.Tests/WorkOrderBoardCreateSyncLockTests.cs
@@ -18,6 +18,7 @@ public class WorkOrderBoardCreateSyncLockTests
             .UseInMemoryDatabase(Guid.NewGuid().ToString())
             .Options;
         await using var context = new ApplicationDbContext(options);
+        WorkOrderAccountTestHelpers.SeedBoardCreateScope(context);
 
         var boardData = new WorkOrderBoardDataService(context);
         var mutationData = new WorkOrderBoardMutationDataService(context);
@@ -37,7 +38,8 @@ public class WorkOrderBoardCreateSyncLockTests
         await createService.CreateAsync(new WorkOrderBoardCreateRequestDto
         {
             WorkOrderType = WorkOrderType.PM,
-            SiteCode = "BK5"
+            SiteCode = "BK5",
+            LocationId = 1
         }, WorkOrderAccountTestHelpers.AccountUser("dispatcher-1"), "dispatcher-1");
 
         var wo = await context.workOrders.SingleAsync();
@@ -65,6 +67,7 @@ public class WorkOrderBoardCreateSyncLockTests
             .UseInMemoryDatabase(Guid.NewGuid().ToString())
             .Options;
         await using var context = new ApplicationDbContext(options);
+        WorkOrderAccountTestHelpers.SeedBoardCreateScope(context);
 
         var boardData = new WorkOrderBoardDataService(context);
         var mutationData = new WorkOrderBoardMutationDataService(context);
@@ -84,7 +87,8 @@ public class WorkOrderBoardCreateSyncLockTests
         await createService.CreateAsync(new WorkOrderBoardCreateRequestDto
         {
             WorkOrderType = WorkOrderType.PM,
-            SiteCode = "BK5"
+            SiteCode = "BK5",
+            LocationId = 1
         }, WorkOrderAccountTestHelpers.AccountUser("dispatcher-1"), "dispatcher-1");
 
         var wo = await context.workOrders.SingleAsync();
diff --git a/SeaHavenIndustries.Tests/WorkOrderPhase7CoexistenceTests.cs b/SeaHavenIndustries.Tests/WorkOrderPhase7CoexistenceTests.cs
index 2b90e5d..31ac539 100644
--- a/SeaHavenIndustries.Tests/WorkOrderPhase7CoexistenceTests.cs
+++ b/SeaHavenIndustries.Tests/WorkOrderPhase7CoexistenceTests.cs
@@ -65,6 +65,7 @@ public class WorkOrderPhase7CoexistenceTests
             .UseInMemoryDatabase(Guid.NewGuid().ToString())
             .Options;
         await using var context = new ApplicationDbContext(options);
+        WorkOrderAccountTestHelpers.SeedBoardCreateScope(context);
 
         var boardData = new WorkOrderBoardDataService(context);
         var mutationData = new WorkOrderBoardMutationDataService(context);
@@ -80,7 +81,8 @@ public class WorkOrderPhase7CoexistenceTests
         await createService.CreateAsync(new WorkOrderBoardCreateRequestDto
         {
             WorkOrderType = WorkOrderType.PM,
-            SiteCode = "BK5"
+            SiteCode = "BK5",
+            LocationId = 1
         }, WorkOrderAccountTestHelpers.AccountUser("dispatcher-1"), "dispatcher-1");
 
         var wo = await context.workOrders.SingleAsync();
diff --git a/docs/adr/0001-work-order-single-org-scope.md b/docs/adr/0001-work-order-single-org-scope.md
index 79b1599..84b8832 100644
--- a/docs/adr/0001-work-order-single-org-scope.md
+++ b/docs/adr/0001-work-order-single-org-scope.md
@@ -12,8 +12,10 @@
   `ApplyAccountScope(int)` when account-scoped; org-wide path skips account filter
 - **Writes** (board mutations, media, board/legacy comments, `POST …/completion-doc`):
   same account filter at service/data entry; authorize before storing blobs
-- **Creates** (board, AddWorkorder, ingest, webhook/recon, sync): stamp `AccountId`
-  from claim or unique `Accounts.Name` ↔ `Customer` match; unresolvable → reject/skip
+- **Creates** (board): stamp `AccountId` from JWT `account_id` or `Location.AccountId`
+  via required `locationId`; body `customer`/`accountId` are not trusted. AddWorkorder,
+  ingest, webhook/recon, sync still stamp from claim or unique `Accounts.Name` ↔
+  `Customer`; unresolvable → reject/skip
 - Missing/malformed scope → **Forbidden** (absence of claim does not elevate)
 
 ## Context (historical)
@@ -31,8 +33,13 @@ in review (fail-open) and replaced by the contract below.
    AccountId). Not inferred from missing `account_id`.
 4. **Fail-closed** = no valid account or org-scope claim → Forbidden.
 5. **Create stamp**:
-   - Authenticated + `account_id` → stamp claim (ignore client AccountId).
-   - Authenticated + `org_scope=all` → unique Customer→Accounts.Name; else
+   - Board `POST /workorders/board`: required `locationId`. Scoped → stamp
+     JWT `account_id` only when `Location.AccountId` matches (else Forbidden).
+     Org-wide → stamp `Location.AccountId`. Missing location → NotFound;
+     null `Location.AccountId` → AccountUnresolved. Body `customer`/`accountId`
+     are ignored for the stamp.
+   - Legacy AddWorkorder: authenticated + `account_id` → stamp claim;
+     authenticated + `org_scope=all` → unique Customer→Accounts.Name; else
      `AccountUnresolved`.
    - Ingest / webhook / sync → same Customer resolution; unresolved create is
      rejected or skipped (no null AccountId on new rows).
@@ -51,8 +58,8 @@ in review (fail-open) and replaced by the contract below.
 - Dispatcher/Manager/Supervisor/User without AccountId cannot access board,
   detail, search, list, or media until AccountId is assigned (or they are Admin
   with `org_scope=all`).
-- Locations do not carry AccountId in the EF model; Customer name match is the
-  unauthenticated resolution path.
+- Board create resolves from `Location.AccountId`. Customer name match remains
+  the ingest/webhook/legacy resolution path.
 
 ## Excepted rule