diff --git a/playwright-local/tests/submit/addressValidation.spec.js b/playwright-local/tests/submit/addressValidation.spec.js
index bea38bb2..9779e779 100644
--- a/playwright-local/tests/submit/addressValidation.spec.js
+++ b/playwright-local/tests/submit/addressValidation.spec.js
@@ -5,29 +5,31 @@ test.describe('Address validation', () => {
 
   test.beforeEach(async ({ page }) => {
     await page.goto('/', { timeout: 30000 });
-  
+
     await page.waitForLoadState('domcontentloaded');
     await page.locator('#field-label--giftaid').click();
     await page.locator('#field-input--mobile').fill('07123456789');
     await page.locator('input#field-input--firstname').fill('test');
     await page.locator('input#field-input--lastname').fill('user');
   });
-  
+
   test('empty postcode should show error message', async ({ page }) => {
     await page.locator('input#field-input--postcode').fill('');
     await page.locator('button[type=submit]').click();
     await expect(page.locator('div#field-error--postcode > span')).toHaveText('Please enter your postcode');
     await page.close();
   });
-  
+
   test('invalid postcodes should show error messages', async ({ page }) => {
     await page.locator('input#field-input--postcode').fill('12SE17TP');
     await expect(page.locator('div#field-error--postcode > span')).toHaveText('Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.');
     await page.locator('input#field-input--postcode').fill('comic relief');
     await expect(page.locator('div#field-error--postcode > span')).toHaveText('Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.');
+    await page.locator('input#field-input--postcode').fill('cro 7tp');
+    await expect(page.locator('div#field-error--postcode > span')).toHaveText('Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.');
     await page.close();
   });
-  
+
   test('enter postcode but submit without selecting address should show error message', async ({ page }) => {
     await page.locator('input#field-input--postcode').fill('SE1 7TP');
     await page.locator('#postcode_button').click();
@@ -36,7 +38,7 @@ test.describe('Address validation', () => {
     await expect(page.locator('div#field-error--addressSelect > span')).toHaveText('Please select your address');
     await page.close();
   });
-  
+
   test('clicking on manual address link should show address fields', async ({ page }) => {
     await page.locator('input#field-input--postcode').fill('SE1 7TP');
     await expect(page.locator('a[aria-describedby=field-error--addressDetails]')).toBeVisible();
@@ -48,17 +50,17 @@ test.describe('Address validation', () => {
     await expect(page.locator('select#field-select--country')).toBeVisible();
     await page.close();
   });
-  
+
   test('validate address fields', async ({ page }) => {
     await page.locator('input#field-input--postcode').fill('SE1 7TP');
     await page.locator('a[aria-describedby=field-error--addressDetails]').click();
-    
+
     // Should see error message for address1 when inout with special characters is entered
     await page.locator('#field-input--address1').fill('@£%3dComic Relief');
     await expect(page.locator('#field-error--address1 > span')).toHaveText("This field only accepts alphanumeric characters and ' . - & _ /");
     await page.locator('#field-input--town').fill('  Comic Relief');
     await expect(page.locator('#field-error--town > span')).toHaveText("This field only accepts alphanumeric characters and ' . - & _ /");
-    
+
     await page.close();
   });
 });
diff --git a/playwright-local/tests/submit/postcodeLookup.spec.js b/playwright-local/tests/submit/postcodeLookup.spec.js
index 229981ac..63959b33 100644
--- a/playwright-local/tests/submit/postcodeLookup.spec.js
+++ b/playwright-local/tests/submit/postcodeLookup.spec.js
@@ -16,8 +16,6 @@ test.describe('Postcode validation', () => {
   test('Postcode formatting errors', async ({ page }) => {
     const postcodes = [
       { code: 'S E 1 7 T P', message: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.' },
-      { code: 'se17tp', message: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.' },
-      { code: 'SE17TP', message: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.' },
       { code: 'SE$%TP', message: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.' }
     ];
     
diff --git a/playwright-local/tests/update/formValidation.spec.js b/playwright-local/tests/update/formValidation.spec.js
index 0a040054..7fee95a5 100644
--- a/playwright-local/tests/update/formValidation.spec.js
+++ b/playwright-local/tests/update/formValidation.spec.js
@@ -7,15 +7,15 @@ const chance = new Chance();
 const email = `giftaid-staging-${Date.now().toString()}@email.sls.comicrelief.com`;
 
 test.describe('Giftaid update form validation', () => {
-  
+
   test.beforeEach(async ({ page }) => {
     await page.goto('/update', { timeout: 30000 });
-    
+
     await page.waitForLoadState('domcontentloaded');
   });
-  
+
   test('empty input fields should show error messages', async ({ page }) => {
-    
+
     // submit the form
     await page.locator('button[type=submit]').click();
 
@@ -23,145 +23,145 @@ test.describe('Giftaid update form validation', () => {
     await expect(page.locator('div#field-error--lastname > span')).toContainText('Please fill in your last name');
     await expect(page.locator('div#field-error--postcode > span')).toContainText('Please enter your postcode');
     await expect(page.locator('div#field-error--addressDetails > span')).toContainText('Please fill in your address');
-    
+
     // click on manual address link to show address fields error messages
     await page.locator('a[aria-describedby=field-error--addressDetails]').click();
     await expect(page.locator('div#field-error--address1 > span')).toContainText('Please fill in your address line 1');
     await expect(page.locator('div#field-error--town > span')).toContainText('Please fill in your town/city');
-    
+
     // giftaid declaration error message
     await expect(page.locator('div#field-error--giftAidClaimChoice > span')).toContainText('This field is required');
 
     await page.close();
   });
-  
-  
+
+
   test('validate first name field on giftaid update form', async ({ page }) => {
-    
+
     const commands = new Commands(page);
-    
+
     await page.locator('#field-input--firstname').fill('test');
     await page.locator('#field-input--firstname').fill('');
     await expect(page.locator('#field-error--firstname')).toContainText('Please fill in your first name');
-    
+
     // enter firstname field with special chars should show error message
     await page.locator('#field-input--firstname').type('Test^$%£');
     await expect(page.locator('#field-error--firstname')).toContainText('This field only accepts alphabetic characters and \' -\n');
-    
+
     // firstname with just a space should show error message
     await page.keyboard.press('Backspace');
     await page.locator('#field-input--firstname').type(' ');
     await expect(page.locator('#field-error--firstname')).toContainText('This field only accepts alphabetic characters and \' -\n');
-    
+
     // firstname with a mixture of alphanumeric chars should show error message
     await page.locator('#field-input--firstname').fill(''); // clear the first-name field
     await page.locator('#field-input--firstname').type('123Test');
     await expect(page.locator('#field-error--firstname')).toContainText('This field only accepts alphabetic characters and \' -\n');
-    
+
     // clear the first name field
     await page.locator('#field-input--firstname').fill('');
-    
+
     // entering valid input fields should be able to submit the form
     await commands.populateUpdateFormFields(page);
 
     // select giftaid declaration
     await page.locator('#giftAidClaimChoice>div:nth-child(2)>label').click();
-    
+
     // submit the form
     await page.locator('button[type=submit]').click();
-    
+
     await expect(page.locator('div > h1')).toContainText('Thank you,\n' +
       'test!');
-    
+
     await page.close();
   });
-  
+
   test('validate last name field on giftaid update form', async ({ page }) => {
-    
+
     const commands = new Commands(page);
-    
+
     await page.locator('#field-input--lastname').fill('test lastname');
     await page.locator('#field-input--lastname').fill('');
     await expect(page.locator('div#field-error--lastname > span')).toContainText('Please fill in your last name');
-    
+
     // enter lastname field with special chars should show error message
     await page.locator('#field-input--lastname').type('Test^$%£');
     await expect(page.locator('div#field-error--lastname > span')).toContainText('This field only accepts alphanumeric characters and , . ( ) / & \' -');
-    
+
     // lastname with just a space should show error message
     await page.keyboard.press('Backspace');
     await page.locator('#field-input--lastname').type(' ');
     await expect(page.locator('div#field-error--lastname > span')).toContainText('This field only accepts alphanumeric characters and , . ( ) / & \' -');
-    
+
     // lastname with a mixture of alphanumeric chars should not show error message
     await page.locator('#field-input--lastname').fill(''); // clear the last-name field
     await page.locator('#field-input--lastname').type('123Test');
     // should not show error message
     expect(await page.locator('div#field-error--lastname > span').count()).toEqual(0);
-    
+
     // clear the last name field
     await page.locator('#field-input--lastname').fill('');
-    
+
     // entering valid input fields should be able to submit the form
     await commands.populateUpdateFormFields(page);
-    
+
     // select giftaid declaration
     await page.locator('#giftAidClaimChoice>div:nth-child(2)>label').click();
-    
+
     // submit the form
     await page.locator('button[type=submit]').click();
-    
+
     await expect(page.locator('div > h1')).toContainText('Thank you,\n' +
       'test!');
-    
+
     await page.close();
-    
+
   });
-  
+
   test('validate email field on giftaid update form', async ({ page }) => {
-    
+
     const commands = new Commands(page);
-    
+
     // email validation
     // email that has $ after the domian name should show error message
     await page.locator('input#field-input--email').fill('test@comic$relief.com');
     await expect(page.locator('div#field-error--email > span')).toContainText('Please fill in a valid email address');
-    
+
     // email that has @ after the domian name should show error message
     await page.locator('input#field-input--email').fill(''); // clear the email field
     await page.locator('input#field-input--email').type('test@c{(micrelief.com');
     await expect(page.locator('div#field-error--email > span')).toContainText('Please fill in a valid email address');
-    
+
     // email that has % after the domian name should show error message
     await page.locator('input#field-input--email').fill('');
     await page.locator('input#field-input--email').type('test@comic%relief.com');
     await expect(page.locator('div#field-error--email > span')).toContainText('Please fill in a valid email address');
-    
+
     // email that has special chars $%^ before domain name should not show error message
     await page.locator('input#field-input--email').fill('');
     await page.locator('input#field-input--email').type('te$%^st@comicrelief.com');
     await expect(page.locator('div#field-error--email > span')).not.toBeVisible();
-    
+
     // email that has mix of special chars that's valid and not valid should show error message
     await page.locator('input#field-input--email').fill('');
     await page.locator('input#field-input--email').type('Test0-9!#$%&\'*+/=?^_{|}~-@comicrelief_9-8.com.uk');
     await expect(page.locator('div#field-error--email > span')).toContainText('Please fill in a valid email address');
-    
+
     // clear the email field
     await page.locator('input#field-input--email').fill('');
-    
+
     // entering valid input fields should be able to submit the form
     await commands.populateUpdateFormFields(page);
 
     // select giftaid declaration
     await page.locator('#giftAidClaimChoice>div:nth-child(2)>label').click();
-  
+
     // submit the form
     await page.locator('button[type=submit]').click();
-    
+
     await expect(page.locator('div > h1')).toContainText('Thank you,\n' +
       'test!');
-    
+
     await page.close();
   });
 
@@ -174,7 +174,7 @@ test.describe('Giftaid update form validation', () => {
     // Generate the remaining 8 digits randomly
     const mobile = `${prefix}${chance.string({ pool: '0123456789', length: 8 })}`;
     console.log('mobile number generated', mobile);
-    
+
     // Test cases for various mobile number validations
     const mobileTestCases = [
       { input: '0722345678', error: 'Please enter a valid mobile phone number - it must be the same number associated with your donation.' },
@@ -184,7 +184,7 @@ test.describe('Giftaid update form validation', () => {
       { input: '07123456789', valid: true },
       { input: '07340707252', valid: true },
     ];
-    
+
     for (let testCase of mobileTestCases) {
       await page.locator('#field-input--mobile').fill(''); // Clear the field before each test
       await page.locator('#field-input--mobile').type(testCase.input, { delay: 100 });
@@ -194,7 +194,7 @@ test.describe('Giftaid update form validation', () => {
         await expect(page.locator('div#field-error--mobile > span')).toHaveText(testCase.error);
       }
     }
-    
+
     // Validate correct mobile number
     await page.locator('#field-input--mobile').fill(''); // Ensure the field is cleared before filling with valid data
 
@@ -206,93 +206,92 @@ test.describe('Giftaid update form validation', () => {
     await page.locator('button[type=submit]').click();
     await expect(page.locator('div > h1')).toHaveText('Thank you, test!');
   });
-  
+
   test('postcode entered with extra spaces should show error message', async ({ page }) => {
-    
+
     await page.locator('input#field-input--postcode').type('S E 1 7 T P');
     await expect(page.locator('div#field-error--postcode > span')).toBeVisible();
     await expect(page.locator('div#field-error--postcode > span')).toContainText('Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.');
-    
+
     await page.close();
   });
-  
-  test('postcode entered in lowercase should show error message', async ({ page }) => {
-    
-    await page.locator('input#field-input--postcode').type('se17tp');
-    await expect(page.locator('div#field-error--postcode > span')).toBeVisible();
-    await expect(page.locator('div#field-error--postcode > span')).toContainText('Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.');
-    
+
+  test('compact lowercase and no-space UK postcodes do not show format error (aligned with data-models / postcode)', async ({ page }) => {
+    await page.locator('input#field-input--postcode').fill('se17tp');
+    await expect(page.locator('div#field-error--postcode > span')).not.toBeVisible();
+    await page.locator('input#field-input--postcode').fill('SE17TP');
+    await expect(page.locator('div#field-error--postcode > span')).not.toBeVisible();
     await page.close();
   });
-  
-  test('postcode entered with no spaces should show error message', async ({ page }) => {
-    
-    await page.locator('input#field-input--postcode').type('SE17TP');
+
+  test('postcode entered with special characters should show error message', async ({ page }) => {
+
+    await page.locator('input#field-input--postcode').type('SE$%TP');
     await expect(page.locator('div#field-error--postcode > span')).toBeVisible();
     await expect(page.locator('div#field-error--postcode > span')).toContainText('Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.');
-    
+
     await page.close();
   });
-  
-  test('postcode entered with special characters should show error message', async ({ page }) => {
-    
-    await page.locator('input#field-input--postcode').type('SE$%TP');
+
+  test('postcode with incorrect format like "cro 7tp" should show error message', async ({ page }) => {
+
+    await page.locator('input#field-input--postcode').type('cro 7tp');
     await expect(page.locator('div#field-error--postcode > span')).toBeVisible();
     await expect(page.locator('div#field-error--postcode > span')).toContainText('Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.');
-    
+
     await page.close();
   });
-  
+
   test('enter valid UK postcode on giftaid update form using postcode lookup should be able to submit the form', async ({ page }) => {
-    
+
     // fill in all input fields
     await page.locator('#field-input--firstname').fill('test');
     await page.locator('#field-input--lastname').fill('test lastname');
     await page.locator('input#field-input--email').fill('giftaid-staging-@email.sls.comicrelief.com');
-    
+
     // enter postcode
     await page.locator('input#field-input--postcode').fill('SE1 7TP');
     // click on postcode lookup button
     await page.locator('#postcode_button').click();
-    
+
     if (await page.locator('#field-select--addressSelect').isVisible()) {
       console.log('postcode lookup address dropdown present select the address');
-      
+
       await expect(page.locator('#field-select--addressSelect')).toBeVisible();
-      
+
       await page.waitForSelector('select#field-select--addressSelect');
-      
+
       const optionToSelect = await page.locator('option', { hasText: 'COMIC RELIEF, CAMELFORD HOUSE 87-90' }).textContent();
       console.log('selected option: ', optionToSelect);
-      
+
       // Use option text to select
       await page.locator('select#field-select--addressSelect').selectOption({ label: optionToSelect });
-      
+
       // expect pre-enetered se17tp postcode to change to SE1 7TP when address is selected by removing the extra spaces
       await expect(page.locator('input#field-input--postcode')).toHaveValue('SE1 7TP');
-      
+
       const addressLine1 = await page.evaluate(() => document.querySelector('#field-input--address1').getAttribute('value'));
       console.log('Address line 1 field value is : ', addressLine1);
-      
+
       const addressLine2 = await page.evaluate(() => document.querySelector('#field-input--address2').getAttribute('value'));
       console.log('Address line 1 field value is : ', addressLine2);
-      
+
       const addressLine3 = await page.evaluate(() => document.querySelector('#field-input--address3').getAttribute('value'));
       console.log('Address line 1 field value is : ', addressLine3);
-      
+
       const town = await page.evaluate(() => document.querySelector('input#field-input--town').getAttribute('value'));
       console.log('Address line 1 field value is : ', town);
 
       // select giftaid declaration
       await page.locator('#giftAidClaimChoice>div:nth-child(2)>label').click();
-      
+
       // clicking on submit button should show error on address lookup
       await page.locator('button[type=submit]').click();
-      
+
       await expect(page.locator('div > h1')).toContainText('Thank you,\n' +
         'test!');
     } else {
-      
+
       // click on manual address link
       await page.locator('a[aria-describedby=field-error--addressDetails]').click();
       await page.locator('#field-input--address1').type('COMIC RELIEF');
@@ -302,10 +301,10 @@ test.describe('Giftaid update form validation', () => {
 
       // select giftaid declaration
       await page.locator('#giftAidClaimChoice>div:nth-child(2)>label').click();
-      
+
       // clicking on submit button should show error on address lookup
       await page.locator('button[type=submit]').click();
-      
+
       await expect(page.locator('div > h1')).toContainText('Thank you,\n' +
         'test!');
     }
diff --git a/playwright-staging/tests/submit/addressValidation.spec.js b/playwright-staging/tests/submit/addressValidation.spec.js
index d2a7915b..1a574546 100644
--- a/playwright-staging/tests/submit/addressValidation.spec.js
+++ b/playwright-staging/tests/submit/addressValidation.spec.js
@@ -3,7 +3,7 @@ const { expect } = require('@playwright/test');
 const { test } = require('../../browserstack');
 
 test.describe('Address validation @sanity @nightly-sanity', () => {
-  
+
   test.beforeEach(async ({ page }) => {
     // Navigate to the giftaid page
     await page.goto(process.env.BASE_URL, { timeout: 30000 });
@@ -13,22 +13,24 @@ test.describe('Address validation @sanity @nightly-sanity', () => {
     await page.locator('input#field-input--firstname').fill('test');
     await page.locator('input#field-input--lastname').fill('user');
   });
-  
+
   test('empty postcode should show error message', async ({ page }) => {
     await page.locator('input#field-input--postcode').fill('');
     await page.locator('button[type=submit]').click();
     await expect(page.locator('div#field-error--postcode > span')).toHaveText('Please enter your postcode');
     await page.close();
   });
-  
+
   test('invalid postcodes should show error messages', async ({ page }) => {
     await page.locator('input#field-input--postcode').fill('12SE17TP');
     await expect(page.locator('div#field-error--postcode > span')).toHaveText('Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.');
     await page.locator('input#field-input--postcode').fill('comic relief');
     await expect(page.locator('div#field-error--postcode > span')).toHaveText('Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.');
+    await page.locator('input#field-input--postcode').fill('cro 7tp');
+    await expect(page.locator('div#field-error--postcode > span')).toHaveText('Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.');
     await page.close();
   });
-  
+
   test('enter postcode but submit without selecting address should show error message', async ({ page }) => {
     await page.locator('input#field-input--postcode').fill('SE1 7TP');
     await page.locator('#postcode_button').click();
@@ -37,7 +39,7 @@ test.describe('Address validation @sanity @nightly-sanity', () => {
     await expect(page.locator('div#field-error--addressSelect > span')).toHaveText('Please select your address');
     await page.close();
   });
-  
+
   test('clicking on manual address link should show address fields', async ({ page }) => {
     await page.locator('input#field-input--postcode').fill('SE1 7TP');
     await expect(page.locator('a[aria-describedby=field-error--addressDetails]')).toBeVisible();
@@ -49,17 +51,17 @@ test.describe('Address validation @sanity @nightly-sanity', () => {
     await expect(page.locator('select#field-select--country')).toBeVisible();
     await page.close();
   });
-  
+
   test('validate address fields', async ({ page }) => {
     await page.locator('input#field-input--postcode').fill('SE1 7TP');
     await page.locator('a[aria-describedby=field-error--addressDetails]').click();
-    
+
     // Should see error message for address1 when inout with special characters is entered
     await page.locator('#field-input--address1').fill('@£%3dComic Relief');
     await expect(page.locator('#field-error--address1 > span')).toHaveText("This field only accepts alphanumeric characters and ' . - & _ /");
     await page.locator('#field-input--town').fill('  Comic Relief');
     await expect(page.locator('#field-error--town > span')).toHaveText("This field only accepts alphanumeric characters and ' . - & _ /");
-    
+
     await page.close();
   });
 });
diff --git a/playwright-staging/tests/submit/postcodeLookup.spec.js b/playwright-staging/tests/submit/postcodeLookup.spec.js
index 79d71b8e..740c4b52 100644
--- a/playwright-staging/tests/submit/postcodeLookup.spec.js
+++ b/playwright-staging/tests/submit/postcodeLookup.spec.js
@@ -16,8 +16,6 @@ test.describe('Postcode validation @sanity @nightly-sanity', () => {
   test('Postcode formatting errors', async ({ page }) => {
     const postcodes = [
       { code: 'S E 1 7 T P', message: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.' },
-      { code: 'se17tp', message: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.' },
-      { code: 'SE17TP', message: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.' },
       { code: 'SE$%TP', message: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.' }
     ];
     
diff --git a/playwright-staging/tests/update/formValidation.spec.js b/playwright-staging/tests/update/formValidation.spec.js
index 9b3dbb40..0c71fe80 100644
--- a/playwright-staging/tests/update/formValidation.spec.js
+++ b/playwright-staging/tests/update/formValidation.spec.js
@@ -8,18 +8,18 @@ const chance = new Chance();
 
 test.describe('Giftaid Update form validation @sanity @nightly-sanity', () => {
   let commands;
-  
+
   test.beforeEach(async ({ page }) => {
-    commands = new Commands(page);    
+    commands = new Commands(page);
     // Navigate to the Giftaid Update form
     await page.goto(`${process.env.BASE_URL}update`, { timeout: 30000 });
     await page.waitForLoadState('domcontentloaded');
   });
-  
+
   test('empty input fields should show error messages', async ({ page }) => {
     // Submit the form without filling out any fields
     await page.click('button[type=submit]');
-    
+
     // Check for the error messages associated with each field
     await expect(page.locator('div#field-error--firstname > span')).toHaveText('Please fill in your first name');
     await expect(page.locator('div#field-error--lastname > span')).toHaveText('Please fill in your last name');
@@ -29,17 +29,17 @@ test.describe('Giftaid Update form validation @sanity @nightly-sanity', () => {
     await expect(page.locator('div#field-error--giftAidClaimChoice > span')).toHaveText('This field is required');
     await page.close();
   });
-  
+
   test('Validate first name field on Giftaid update form', async ({ page }) => {
     const commands = new Commands(page);
-    
+
     // Set up different first name test cases
     const firstNameTestCases = [
       { input: 'Test^$%£', error: "This field only accepts alphabetic characters and ' -" },  // Test for invalid characters
       { input: ' ', error: "This field only accepts alphabetic characters and ' -" },  // Test for space as input
       { input: '123Test', error: "This field only accepts alphabetic characters and ' -" }  // Test for alphanumeric input
     ];
-    
+
     for (let testCase of firstNameTestCases) {
       await page.fill('#field-input--firstname', testCase.input);
       if (testCase.input) {
@@ -47,20 +47,20 @@ test.describe('Giftaid Update form validation @sanity @nightly-sanity', () => {
       }
       await expect(page.locator('#field-error--firstname')).toHaveText(testCase.error);
     }
-    
+
     // Test for a valid first name
     await page.fill('#field-input--firstname', ''); // clear firstname field
     await commands.populateUpdateFormFields(page, { firstName: 'John' });
     await page.click('#giftAidClaimChoice>div:nth-child(2)>label'); // Select yes for declaration
     await page.click('button[type=submit]');  // Submit the form
-    
+
     await expect(page.locator('div.success-wrapper--inner h1')).toHaveText('Thank you, John!');
     await page.close();
   });
-  
+
   test('Validate email field on giftaid update form', async ({ page }) => {
     const commands = new Commands(page);
-    
+
     // Set up different email test cases
     const emailTestCases = [
       { input: 'test@comic$relief.com', error: 'Please fill in a valid email address', visible: true },
@@ -69,7 +69,7 @@ test.describe('Giftaid Update form validation @sanity @nightly-sanity', () => {
       { input: 'te$%^st@comicrelief.com', error: '', visible: false },
       { input: 'Test0-9!#$%&\'*+/=?^_{|}~-@comicrelief_9-8.com.uk', error: 'Please fill in a valid email address', visible: true }
     ];
-    
+
     for (let testCase of emailTestCases) {
       await page.fill('input#field-input--email', ''); // clear the email field before entering the test cases input
       await page.fill('input#field-input--email', testCase.input);
@@ -81,18 +81,18 @@ test.describe('Giftaid Update form validation @sanity @nightly-sanity', () => {
         await expect(page.locator('div#field-error--email > span')).not.toBeVisible();
       }
     }
-    
+
     // Test for a valid email
     const validEmail = `giftaid-update-staging-${chance.email()}`;
     await page.fill('input#field-input--email', ''); // clear email field
     await commands.populateUpdateFormFields(page, { email: validEmail });
     await page.click('#giftAidClaimChoice>div:nth-child(3)>label'); // Select no for declaration
     await page.click('button[type=submit]'); // Submit the form
-    
+
     await expect(page.locator('div.success-wrapper--inner h1')).toHaveText('Thanks for letting us know');
     await page.close();
   });
-  
+
   test('Validate mobile number field on giftaid update form', async ({ page }) => {
     const commands = new Commands(page);
     // List of allowed prefixes for UK mobile numbers
@@ -102,7 +102,7 @@ test.describe('Giftaid Update form validation @sanity @nightly-sanity', () => {
     // Generate the remaining 8 digits randomly
     const mobile = `${prefix}${chance.string({ pool: '0123456789', length: 8 })}`;
     console.log('mobile number generated', mobile);
-    
+
     // Test cases for various mobile number validations
     const mobileTestCases = [
       { input: '0722345678', error: 'Please enter a valid mobile phone number - it must be the same number associated with your donation.' },
@@ -112,7 +112,7 @@ test.describe('Giftaid Update form validation @sanity @nightly-sanity', () => {
       { input: '07123456789', valid: true },
       { input: '07340707252', valid: true },
     ];
-    
+
     for (let testCase of mobileTestCases) {
       await page.locator('#field-input--mobile').fill(''); // Clear the field before each test
       await page.locator('#field-input--mobile').type(testCase.input, { delay: 100 });
@@ -122,25 +122,24 @@ test.describe('Giftaid Update form validation @sanity @nightly-sanity', () => {
         await expect(page.locator('div#field-error--mobile > span')).toHaveText(testCase.error);
       }  
     }
-    
+
     // Validate correct mobile number
     await page.locator('#field-input--mobile').fill(''); // Ensure the field is cleared and filled with valid data
     await commands.populateUpdateFormFields(page, { lastName: 'test', mobile: mobile });
     await page.click('#giftAidClaimChoice>div:nth-child(2)>label'); // Select yes for declaration
     await page.click('button[type=submit]'); // Submit the form
-  
+
     await expect(page.locator('div.success-wrapper--inner h1')).toHaveText('Thank you,  test!');
   });
-  
+
   test('Postcode validation and form submission', async ({ page }) => {
     // Define postcodes and expected error messages
     const postcodes = [
       { input: 'S E 1 7 T P', error: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.' },
-      { input: 'se17tp', error: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.' },
-      { input: 'SE17TP', error: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.' },
-      { input: 'SE$%TP', error: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.' }
+      { input: 'SE$%TP', error: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.' },
+      { input: 'cro 7tp', error: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.' }
     ];
-    
+
     // Test for each invalid postcode
     for (const postcode of postcodes) {
       await page.fill('input#field-input--postcode', '');
@@ -148,11 +147,11 @@ test.describe('Giftaid Update form validation @sanity @nightly-sanity', () => {
       await expect(page.locator('div#field-error--postcode > span')).toBeVisible();
       await expect(page.locator('div#field-error--postcode > span')).toHaveText(postcode.error);
     }
-    
+
     // Test for a valid postcode and subsequent form submission
     await page.fill('input#field-input--postcode', 'SE1 7TP');
     await page.click('#postcode_button');
-    
+
     // Checking whether address selection is available or if manual entry is needed
     if (await page.locator('#field-select--addressSelect').isVisible()) {
       // Select the first address if available
@@ -168,14 +167,14 @@ test.describe('Giftaid Update form validation @sanity @nightly-sanity', () => {
       await page.fill('input#field-input--town', 'LONDON');
       await page.click('button[type=submit]');
     }
-  
+
     await page.locator('input#field-input--firstname').fill('test');
     await page.locator('input#field-input--lastname').fill(chance.last());
     await page.locator('input#field-input--email').fill(`giftaid-update-staging-${chance.email()}`);
     await page.fill('input#field-input--postcode', 'SE1 7TP');
     await page.click('#giftAidClaimChoice>div:nth-child(2)>label'); // Select yes for declaration
     await page.click('button[type=submit]'); // Submit the form
-    
+
     await expect(page.locator('div.success-wrapper--inner h1')).toHaveText('Thank you,  test!');
     await page.close();
   });
diff --git a/src/pages/GiftAid/SubmitForm/SubmitForm.js b/src/pages/GiftAid/SubmitForm/SubmitForm.js
index d7c45b21..a32fba14 100644
--- a/src/pages/GiftAid/SubmitForm/SubmitForm.js
+++ b/src/pages/GiftAid/SubmitForm/SubmitForm.js
@@ -9,6 +9,7 @@ import FormHeader from '../../../components/FormHeader/FormHeader';
 import FormButton from '../../../components/Buttons/FormButton/index';
 import InputFields from '../../../components/InputFields/InputFields';
 import JustInTime from '../../../components/JustInTime/index';
+import { postcodeRegex } from '../utils/Utils';
 
 // fields data
 import { submitFormFields } from './SubmitFormFields';
@@ -103,6 +104,7 @@ function SubmitForm(props) {
             Object.keys(validation).map(key => setFieldValidity(validation[key], key));
           }
         }
+        postcodeValidation={postcodeRegex}
       />
 
       <MarketingConsent
@@ -114,10 +116,10 @@ function SubmitForm(props) {
         {...marketingProps}
       />
 
-      <FormButton 
+      <FormButton
         isSubmitting={isSubmitting}
         onClick={(e) => submitForm(e)}
-        text="Gift Aid your donation" 
+        text="Gift Aid your donation"
       />
 
       <JustInTime submit text={justInTimeLinkText} />
diff --git a/src/pages/GiftAid/UpdateForm/UpdateForm.js b/src/pages/GiftAid/UpdateForm/UpdateForm.js
index f834a3eb..a1dfdaf3 100644
--- a/src/pages/GiftAid/UpdateForm/UpdateForm.js
+++ b/src/pages/GiftAid/UpdateForm/UpdateForm.js
@@ -11,6 +11,7 @@ import JustInTime from '../../../components/JustInTime/index';
 
 // fields data
 import { updateFormFields, giftAidButtonChoices } from './UpdateFormFields';
+import { postcodeRegex } from '../utils/Utils';
 
 // import context
 import FormContext from '../../../context/FormContext';
@@ -67,6 +68,7 @@ function UpdateForm(props) {
               Object.keys(validation).map(key => setFieldValidity(validation[key], key));
             }
           }
+          postcodeValidation={postcodeRegex}
         />
 
       </div>
diff --git a/src/pages/GiftAid/utils/Utils.js b/src/pages/GiftAid/utils/Utils.js
index fccc5697..bbdcebf1 100644
--- a/src/pages/GiftAid/utils/Utils.js
+++ b/src/pages/GiftAid/utils/Utils.js
@@ -51,6 +51,13 @@ export const getPathParams = (update = false) => {
   };
 };
 
+// Regex matches what we use in data-models, which the backend uses to validate postcodes.
+export const postcodeRegex = {
+  GB: {
+    pattern: '^[A-Za-z]{1,2}\\d[A-Za-z\\d]?\\s*\\d[A-Za-z]{2}$',
+    errorMsg: 'Please enter a valid UK postcode, using a space. For non-UK addresses, please use manual entry below.',
+  },
+};
 
 /**
  * Function to Create form fields