diff --git a/apps/desktop/src/auth/delete-account.component.html b/apps/desktop/src/auth/delete-account.component.html
index 08448e2422d..f8cc671af82 100644
--- a/apps/desktop/src/auth/delete-account.component.html
+++ b/apps/desktop/src/auth/delete-account.component.html
@@ -6,7 +6,7 @@
       <bit-callout type="warning" title="{{ 'warning' | i18n }}">
         {{ "deleteAccountWarning" | i18n }}
       </bit-callout>
-      @if (migrationMilestone3) {
+      @if (migrationMilestone4) {
         <app-user-verification-form-input
           formControlName="verification"
           verificationType="server"
diff --git a/apps/desktop/src/auth/delete-account.component.spec.ts b/apps/desktop/src/auth/delete-account.component.spec.ts
new file mode 100644
index 00000000000..b699045519b
--- /dev/null
+++ b/apps/desktop/src/auth/delete-account.component.spec.ts
@@ -0,0 +1,121 @@
+import { FormBuilder } from "@angular/forms";
+import { MockProxy, mock } from "jest-mock-extended";
+
+import { AccountApiService } from "@bitwarden/common/auth/abstractions/account-api.service";
+import { VerificationWithSecret } from "@bitwarden/common/auth/types/verification";
+import { ConfigService } from "@bitwarden/common/platform/abstractions/config/config.service";
+import { I18nService } from "@bitwarden/common/platform/abstractions/i18n.service";
+import { ToastService } from "@bitwarden/components";
+
+import { DeleteAccountComponent } from "./delete-account.component";
+
+describe("DeleteAccountComponent", () => {
+  let component: DeleteAccountComponent;
+  let i18nService: MockProxy<I18nService>;
+  let formBuilder: FormBuilder;
+  let accountApiService: MockProxy<AccountApiService>;
+  let toastService: MockProxy<ToastService>;
+  let configService: MockProxy<ConfigService>;
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+
+    i18nService = mock<I18nService>();
+    formBuilder = new FormBuilder();
+    accountApiService = mock<AccountApiService>();
+    toastService = mock<ToastService>();
+    configService = mock<ConfigService>();
+
+    i18nService.t.mockImplementation((key: any) => key);
+
+    component = new DeleteAccountComponent(
+      i18nService,
+      formBuilder,
+      accountApiService,
+      toastService,
+      configService,
+    );
+  });
+
+  describe("submit", () => {
+    const mockVerification: VerificationWithSecret = {
+      type: 0,
+      secret: "masterPassword123",
+    };
+
+    beforeEach(() => {
+      component.deleteForm.patchValue({
+        verification: mockVerification,
+      });
+    });
+
+    describe("when feature flag is enabled", () => {
+      beforeEach(() => {
+        component["migrationMilestone4"] = true;
+      });
+
+      it("should delete account and show success toast on successful deletion", async () => {
+        accountApiService.deleteAccount.mockResolvedValue(undefined);
+
+        await component.submit();
+
+        expect(accountApiService.deleteAccount).toHaveBeenCalledWith(mockVerification);
+        expect(toastService.showToast).toHaveBeenCalledWith({
+          variant: "success",
+          title: "accountDeleted",
+          message: "accountDeletedDesc",
+        });
+        expect(component["invalidSecret"]).toBe(false);
+      });
+
+      it("should set invalidSecret to true when deletion fails", async () => {
+        accountApiService.deleteAccount.mockRejectedValue(new Error("Invalid credentials"));
+
+        await component.submit();
+
+        expect(accountApiService.deleteAccount).toHaveBeenCalledWith(mockVerification);
+        expect(toastService.showToast).not.toHaveBeenCalled();
+        expect(component["invalidSecret"]).toBe(true);
+      });
+
+      it("should reset invalidSecret to false before attempting deletion", async () => {
+        component["invalidSecret"] = true;
+        accountApiService.deleteAccount.mockResolvedValue(undefined);
+
+        await component.submit();
+
+        expect(component["invalidSecret"]).toBe(false);
+      });
+    });
+
+    describe("when feature flag is disabled", () => {
+      beforeEach(() => {
+        component["migrationMilestone4"] = false;
+      });
+
+      it("should delete account and show success toast on successful deletion", async () => {
+        accountApiService.deleteAccount.mockResolvedValue(undefined);
+
+        await component.submit();
+
+        expect(accountApiService.deleteAccount).toHaveBeenCalledWith(mockVerification);
+        expect(toastService.showToast).toHaveBeenCalledWith({
+          variant: "success",
+          title: "accountDeleted",
+          message: "accountDeletedDesc",
+        });
+      });
+
+      it("should not set invalidSecret when deletion fails", async () => {
+        const initialInvalidSecret = component["invalidSecret"];
+        accountApiService.deleteAccount.mockRejectedValue(new Error("Invalid credentials"));
+
+        await component.submit();
+
+        expect(accountApiService.deleteAccount).toHaveBeenCalledWith(mockVerification);
+        expect(toastService.showToast).not.toHaveBeenCalled();
+        expect(component["invalidSecret"]).toBe(initialInvalidSecret);
+      });
+    });
+  });
+});
diff --git a/apps/desktop/src/auth/delete-account.component.ts b/apps/desktop/src/auth/delete-account.component.ts
index b3bad0eba96..15c2b9d669d 100644
--- a/apps/desktop/src/auth/delete-account.component.ts
+++ b/apps/desktop/src/auth/delete-account.component.ts
@@ -50,9 +50,9 @@ export class DeleteAccountComponent implements OnInit {
   protected invalidSecret = false;
 
   /**
-   * Feature flag for UI Migration Milestone 3
+   * Feature flag for UI Migration Milestone 4
    */
-  protected migrationMilestone3 = false;
+  protected migrationMilestone4 = false;
 
   constructor(
     private i18nService: I18nService,
@@ -63,8 +63,8 @@ export class DeleteAccountComponent implements OnInit {
   ) {}
 
   async ngOnInit() {
-    this.migrationMilestone3 = await this.configService.getFeatureFlag(
-      FeatureFlag.DesktopUiMigrationMilestone3,
+    this.migrationMilestone4 = await this.configService.getFeatureFlag(
+      FeatureFlag.DesktopUiMigrationMilestone4,
     );
   }
 
@@ -78,8 +78,8 @@ export class DeleteAccountComponent implements OnInit {
 
   submit = async () => {
     try {
-      if (this.migrationMilestone3) {
-        this.invalidSecret = false; // Reset error state before attempting
+      if (this.migrationMilestone4) {
+        this.invalidSecret = false;
       }
       const verification = this.deleteForm.get("verification").value;
       await this.accountApiService.deleteAccount(verification);
@@ -89,7 +89,7 @@ export class DeleteAccountComponent implements OnInit {
         message: this.i18nService.t("accountDeletedDesc"),
       });
     } catch {
-      if (this.migrationMilestone3) {
+      if (this.migrationMilestone4) {
         this.invalidSecret = true;
       }
     }
diff --git a/libs/common/src/enums/feature-flag.enum.ts b/libs/common/src/enums/feature-flag.enum.ts
index f3afd03b975..5684f6e977a 100644
--- a/libs/common/src/enums/feature-flag.enum.ts
+++ b/libs/common/src/enums/feature-flag.enum.ts
@@ -77,8 +77,9 @@ export enum FeatureFlag {
 
   /* Desktop */
   DesktopUiMigrationMilestone1 = "desktop-ui-migration-milestone-1",
-  DesktopUiMigrationMilestone3 = "desktop-ui-migration-milestone-3",
   DesktopUiMigrationMilestone2 = "desktop-ui-migration-milestone-2",
+  DesktopUiMigrationMilestone3 = "desktop-ui-migration-milestone-3",
+  DesktopUiMigrationMilestone4 = "desktop-ui-migration-milestone-4",
 
   /* UIF */
   RouterFocusManagement = "router-focus-management",
@@ -168,8 +169,9 @@ export const DefaultFeatureFlagValue = {
 
   /* Desktop */
   [FeatureFlag.DesktopUiMigrationMilestone1]: FALSE,
-  [FeatureFlag.DesktopUiMigrationMilestone3]: FALSE,
   [FeatureFlag.DesktopUiMigrationMilestone2]: FALSE,
+  [FeatureFlag.DesktopUiMigrationMilestone3]: FALSE,
+  [FeatureFlag.DesktopUiMigrationMilestone4]: FALSE,
 
   /* UIF */
   [FeatureFlag.RouterFocusManagement]: FALSE,
@@ -186,12 +188,6 @@ export function getFeatureFlagValue<Flag extends FeatureFlag>(
   serverConfig: ServerConfig | null,
   flag: Flag,
 ) {
-  if (flag === FeatureFlag.DesktopUiMigrationMilestone1) {
-    return true;
-  }
-  if (flag === FeatureFlag.DesktopUiMigrationMilestone3) {
-    return true;
-  }
   if (serverConfig?.featureStates == null || serverConfig.featureStates[flag] == null) {
     return DefaultFeatureFlagValue[flag];
   }