diff --git a/application/CohortManager/src/Web/tests/features/home.feature b/application/CohortManager/src/Web/tests/features/home.feature
index d9252ae496..c41e9ab6f6 100644
--- a/application/CohortManager/src/Web/tests/features/home.feature
+++ b/application/CohortManager/src/Web/tests/features/home.feature
@@ -46,3 +46,22 @@ Feature: testing Breast screening - Cohort Manager home page
   Scenario: verify navigation to cookies screen
     And the user clicks on cookies link
     Then they should navigate to 'Cookies on Cohort Manager - Cohort Manager - NHS'
+
+  @epic_4a @req_6330
+  Scenario: verify error message for invalid URL
+    When the user navigates to an invalid URL
+    Then the page should display 'Page not found' on screen
+    And the page not found error screen should include a 'Return to the homepage' link
+    And the page not found error screen should include a 'Contact us' link
+
+  @epic_4a @req_6330
+  Scenario: verify navigation to home from error page
+    When the user navigates to an invalid URL
+    And the user clicks on the 'Return to the homepage' link
+    Then they should navigate to 'Breast screening - Cohort Manager - NHS'
+
+  @epic_4a @req_6330
+  Scenario: verify navigation to contact us from error page
+    When the user navigates to an invalid URL
+    And the user clicks on the 'Contact us' link
+    Then they should navigate to 'Get help with Cohort Manager - Cohort Manager - NHS'
diff --git a/application/CohortManager/src/Web/tests/features/steps/homeSteps.ts b/application/CohortManager/src/Web/tests/features/steps/homeSteps.ts
index 3ac985e800..f12ed5380c 100644
--- a/application/CohortManager/src/Web/tests/features/steps/homeSteps.ts
+++ b/application/CohortManager/src/Web/tests/features/steps/homeSteps.ts
@@ -94,3 +94,20 @@ When('the user clicks on cookies link', async ({ page }) => {
   homePage = new HomePage(page);
   await homePage.clickOnCookiesLink()
 });
+When('the user navigates to an invalid URL', async ({ page }) => {
+  // Navigate to a non-existent page to trigger 404
+  await page.goto('https://localhost:3000/exception');
+});
+Then("the page should display {string} on screen", async ({ page }, errorType) => {
+  // Check for a heading or text that indicates 404
+  await expect(page.getByRole('heading', { name: new RegExp(errorType, 'i') })).toBeVisible();
+});
+Then("the page not found error screen should include a {string} link", async ({ page }, link) => {
+  // Check for the presence of the return link
+  const linkLocator = page.getByRole('link', { name: new RegExp(link, 'i') }).first();
+  await expect(linkLocator).toBeVisible();
+});
+When('the user clicks on the {string} link', async ({ page }, linkText) => {
+  const linkLocator = page.getByRole('link', { name: new RegExp(linkText, 'i') }).first();
+  await linkLocator.click();
+});