Just found this under the common questions section:
- In store?
You can spend your points any time on almost anything in store**. When you get to the till just hand over your Advantage Card and let the cashier know you would like to pay with points. You'll need the full amount of points for the product you choose. The total price in points will simply be taken from your Advantage Card.
**We're sorry but points cannot be spent in Boots Opticians or on Boots.com. In stores points can't be spent on prescription items, stamps, gift vouchers/cards, infant milks (up to 6 months), mobile phone top-up cards and insurance products. Please look for the * on the price ticket as this tells you that you can pay with points.
- Online?
Unfortunately you can't spend your points online, but you can still spend points in store that you've collected online. To collect these points you'll need to visit one of our Extra Offer Kiosks, found in larger Boots stores. Simply insert your permanent Advantage Card in to any of our Extra Offer Kiosks and your points will be automatically added to your card.