Here's how it works:
1. Make a purchase of at least £25 of eligible items on Amazon.co.uk (not marketplace items, and not gift cards).
2. Enter the promo code AMEX16SWP in the box provided on the checkout page and pay for at least a portion of your order with Membership Rewards points.
3. After choosing your membership rewards-enrolled Amex card (e.g. gold, platinum, green) you'll be given the option to part pay with MR points. Apply a minimum of 2 points (£0.01)
4. Enjoy £15 off your purchase!