diff --git a/DigitalLearningSolutions.Web.Tests/Controllers/TrackingSystem/Delegates/DeactivateDelegateControllerTests.cs b/DigitalLearningSolutions.Web.Tests/Controllers/TrackingSystem/Delegates/DeactivateDelegateControllerTests.cs
new file mode 100644
index 0000000000..3cd25f78df
--- /dev/null
+++ b/DigitalLearningSolutions.Web.Tests/Controllers/TrackingSystem/Delegates/DeactivateDelegateControllerTests.cs
@@ -0,0 +1,161 @@
+using DigitalLearningSolutions.Web.Controllers.TrackingSystem.Delegates;
+using DigitalLearningSolutions.Web.Services;
+using DigitalLearningSolutions.Web.Tests.ControllerHelpers;
+using DigitalLearningSolutions.Web.Tests.TestHelpers;
+using DigitalLearningSolutions.Web.Helpers;
+using FakeItEasy;
+using FluentAssertions;
+using FluentAssertions.AspNetCore.Mvc;
+using NUnit.Framework;
+using DigitalLearningSolutions.Web.ViewModels.TrackingSystem.Delegates.DeactivateDelegate;
+using DigitalLearningSolutions.Data.Models.User;
+using System.Collections.Generic;
+
+namespace DigitalLearningSolutions.Web.Tests.Controllers.TrackingSystem.Delegates
+{
+    public class DeactivateDelegateControllerTests
+    {
+        private const int DelegateId = 1;
+        private DeactivateDelegateController controller = null!;
+        private IUserService userService = null!;
+
+        [SetUp]
+        public void SetUp()
+        {
+            userService = A.Fake<IUserService>();
+
+            controller = new DeactivateDelegateController(userService)
+                .WithDefaultContext()
+                .WithMockUser(true);
+        }
+
+        [Test]
+        public void Index_returns_not_found_with_null_delegate()
+        {
+            // Given
+            A.CallTo(() => userService.CheckDelegateIsActive(DelegateId)).Returns(null);
+
+            // When
+            var result = controller.Index(DelegateId);
+
+            // Then
+            result.Should()
+               .BeRedirectToActionResult()
+               .WithControllerName("LearningSolutions")
+               .WithActionName("StatusCode")
+               .WithRouteValue("code", 410);
+        }
+
+        [Test]
+        public void Index_returns_view_when_service_returns_valid_delegate()
+        {
+            // Given
+            A.CallTo(() => userService.CheckDelegateIsActive(DelegateId)).Returns(DelegateId);
+            int? centreId = controller.User.GetCentreId();
+
+            var delegateEntity = UserTestHelper.GetDefaultDelegateEntity(DelegateId, centreId.Value);
+            A.CallTo(() => userService.GetDelegateById(DelegateId)).Returns(delegateEntity);
+
+            var userEntity = new UserEntity(
+                UserTestHelper.GetDefaultUserAccount(),
+                new List<AdminAccount> { UserTestHelper.GetDefaultAdminAccount(centreId.Value) },
+                new List<DelegateAccount> { UserTestHelper.GetDefaultDelegateAccount(centreId.Value) }
+            );
+
+            A.CallTo(() => userService.GetUserById(delegateEntity.DelegateAccount.UserId)).Returns(userEntity);
+
+            // When
+            var result = controller.Index(DelegateId);
+
+            // Then
+            result.Should().BeViewResult().WithDefaultViewName();
+            result.Should().BeViewResult().ModelAs<DeactivateDelegateAccountViewModel>().DelegateId.Should().Be(DelegateId);
+            result.Should().BeViewResult().ModelAs<DeactivateDelegateAccountViewModel>().Name.Should().Be(delegateEntity.UserAccount.FirstName + " " + delegateEntity.UserAccount.LastName);
+            result.Should().BeViewResult().ModelAs<DeactivateDelegateAccountViewModel>().Email.Should().Be(delegateEntity.UserAccount.PrimaryEmail);
+            result.Should().BeViewResult().ModelAs<DeactivateDelegateAccountViewModel>().UserId.Should().Be(delegateEntity.UserAccount.Id);
+        }
+
+        [Test]
+        public void Index_post_returns_error_when_no_option_selected_to_deactivate()
+        {
+            // Given
+            var formData = new DeactivateDelegateAccountViewModel
+            {
+                DelegateId = 1,
+                Name = "Firstname Test",
+                Roles = new List<string>(),
+                Email = "email@test.com",
+                UserId = 2,
+                Deactivate = null
+            };
+
+            controller.ModelState.AddModelError("key", "Invalid for testing.");
+
+            // When
+            var result = controller.Index(formData);
+
+            // Then
+            result.Should().BeViewResult().ModelAs<DeactivateDelegateAccountViewModel>().DelegateId.Should().Be(DelegateId);
+            Assert.IsFalse(controller.ModelState.IsValid);
+        }
+
+
+        [Test]
+        public void Index_post_returns_view_for_deactivate_delegate_only()
+        {
+            // Given
+            int? centreId = controller.User.GetCentreId();
+            var formData = new DeactivateDelegateAccountViewModel
+            {
+                DelegateId = 1,
+                Name = "Firstname Test",
+                Roles = new List<string>(),
+                Email = "email@test.com",
+                UserId = 2,
+                Deactivate = true
+            };
+
+            // When
+            var result = controller.Index(formData);
+
+            // Then
+            A.CallTo(() => userService.DeactivateDelegateUser(DelegateId)).MustHaveHappenedOnceExactly();
+            A.CallTo(() => userService.DeactivateAdminAccount(formData.UserId, centreId.Value)).MustNotHaveHappened();
+
+            result.Should().BeRedirectToActionResult()
+                .WithControllerName("ViewDelegate")
+                .WithActionName("Index")
+                .WithRouteValue("delegateId", formData.DelegateId);
+
+        }
+
+        [Test]
+        public void Index_post_returns_view_for_deactivate_delegate_and_admin()
+        {
+            // Given
+            int? centreId = controller.User.GetCentreId();
+            var formData = new DeactivateDelegateAccountViewModel
+            {
+                DelegateId = 1,
+                Name = "Firstname Test",
+                Roles = new List<string>(),
+                Email = "email@test.com",
+                UserId = 2,
+                Deactivate = false
+            };
+
+            // When
+            var result = controller.Index(formData);
+
+            // Then
+            A.CallTo(() => userService.DeactivateDelegateUser(DelegateId)).MustHaveHappenedOnceExactly();
+            A.CallTo(() => userService.DeactivateAdminAccount(formData.UserId, centreId.Value)).MustHaveHappenedOnceExactly();
+
+            result.Should().BeRedirectToActionResult()
+                .WithControllerName("ViewDelegate")
+                .WithActionName("Index")
+                .WithRouteValue("delegateId", formData.DelegateId);
+        }
+
+    }
+}