Instructions:Just got the following email from Amazon. Dear Amazon.co.uk Customer,
Get £5 for yourself when you buy at least £20 in Amazon Gift Cards on Amazon.co.uk by 20 December, 2014.
Enter "XMASGIFT20" when you check out with your £20 gift card purchase, to qualify for the £5 promotional code.
You will receive the £5 promotional code by e-mail within 5 days of your gift card purchase.