diff --git a/Api.SeaHavenIndustries.Tests/VendorControllerTests.cs b/Api.SeaHavenIndustries.Tests/VendorControllerTests.cs
new file mode 100644
index 0000000..4357926
--- /dev/null
+++ b/Api.SeaHavenIndustries.Tests/VendorControllerTests.cs
@@ -0,0 +1,107 @@
+using Api.SeaHavenIndustries.Controllers;
+using Api.SeaHavenIndustries.DTOs;
+using FluentAssertions;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using Moq;
+using SeaHaven.Services.DTOs;
+using SeaHaven.Services.Interfaces;
+using System.Security.Claims;
+using Xunit;
+
+namespace Api.SeaHavenIndustries.Tests;
+
+public class VendorControllerTests
+{
+    private static VendorController NewController(Mock<IVendorService> service)
+    {
+        var controller = new VendorController(
+            service.Object,
+            db: null!,
+            zipDistance: null!,
+            vendorTokens: null!,
+            config: null!);
+
+        controller.ControllerContext = new ControllerContext
+        {
+            HttpContext = new DefaultHttpContext
+            {
+                User = new ClaimsPrincipal(new ClaimsIdentity(new[]
+                {
+                    new Claim(ClaimTypes.NameIdentifier, "42")
+                }, "Test"))
+            }
+        };
+
+        return controller;
+    }
+
+    [Fact]
+    public async Task Update_WithoutIsActive_PassesNullToServiceToPreserveStatus()
+    {
+        var service = new Mock<IVendorService>();
+        service.Setup(x => x.UpdateVendorAsync(It.IsAny<int>(), It.IsAny<UpdateVendorDTO>(), It.IsAny<string>()))
+            .ReturnsAsync(new VendorDTO());
+
+        var controller = NewController(service);
+
+        var model = new EditVendor_DTO
+        {
+            Id = 8,
+            CompanyName = "Updated Name"
+        };
+
+        var result = await controller.Update(8, model);
+
+        result.Should().BeOfType<OkObjectResult>();
+        service.Verify(x => x.UpdateVendorAsync(
+            8,
+            It.Is<UpdateVendorDTO>(dto => dto.IsActive == null),
+            "42"), Times.Once);
+    }
+
+    [Fact]
+    public async Task Update_WithExplicitIsActive_ForwardsValueUnchanged()
+    {
+        var service = new Mock<IVendorService>();
+        service.Setup(x => x.UpdateVendorAsync(It.IsAny<int>(), It.IsAny<UpdateVendorDTO>(), It.IsAny<string>()))
+            .ReturnsAsync(new VendorDTO());
+
+        var controller = NewController(service);
+
+        var model = new EditVendor_DTO
+        {
+            Id = 8,
+            CompanyName = "Updated Name",
+            IsActive = false
+        };
+
+        await controller.Update(8, model);
+
+        service.Verify(x => x.UpdateVendorAsync(
+            8,
+            It.Is<UpdateVendorDTO>(dto => dto.IsActive == false),
+            "42"), Times.Once);
+    }
+
+    [Fact]
+    public async Task Create_WithoutIsActive_DefaultsToActive()
+    {
+        var service = new Mock<IVendorService>();
+        service.Setup(x => x.CreateVendorAsync(It.IsAny<CreateVendorDTO>(), It.IsAny<string>()))
+            .ReturnsAsync(new VendorDTO());
+
+        var controller = NewController(service);
+
+        var model = new Vendor_DTO
+        {
+            CompanyName = "New Co"
+        };
+
+        await controller.Create(model);
+
+        service.Verify(x => x.CreateVendorAsync(
+            It.Is<CreateVendorDTO>(dto => dto.IsActive == true),
+            "42"), Times.Once);
+    }
+}
diff --git a/Api.SeaHavenIndustries/Controllers/VendorController.cs b/Api.SeaHavenIndustries/Controllers/VendorController.cs
index a1ae149..143f5ce 100644
--- a/Api.SeaHavenIndustries/Controllers/VendorController.cs
+++ b/Api.SeaHavenIndustries/Controllers/VendorController.cs
@@ -134,7 +134,7 @@ namespace Api.SeaHavenIndustries.Controllers
                     TradeSpecialties = model.TradeSpecialties,
                     GoogleMapsUrl = model.GoogleMapsUrl,
                     Notes = model.Notes,
-                    IsActive = model.IsActive
+                    IsActive = model.IsActive ?? true
                 };
 
                 var userId = User.FindFirstValue(ClaimTypes.NameIdentifier);
diff --git a/Api.SeaHavenIndustries/DTOs/Vendor_DTO.cs b/Api.SeaHavenIndustries/DTOs/Vendor_DTO.cs
index 0d167da..d2a4717 100644
--- a/Api.SeaHavenIndustries/DTOs/Vendor_DTO.cs
+++ b/Api.SeaHavenIndustries/DTOs/Vendor_DTO.cs
@@ -14,7 +14,7 @@ namespace Api.SeaHavenIndustries.DTOs
         public string? TradeSpecialties { get; set; }
         public string? GoogleMapsUrl { get; set; }
         public string? Notes { get; set; }
-        public bool IsActive { get; set; } = true;
+        public bool? IsActive { get; set; }
     }
 
     public class EditVendor_DTO : Vendor_DTO