10% Discount for UK order not applied

Going through the motions of placing an order via this page
http://aerodrums.com/product/aerodrums-and-camera-ships-by-february-22nd/
I notice that the 10% discount doesn't get carried through to the Cart Page
http://aerodrums.com/product/aerodrums-and-camera-ships-by-february-22nd/
I notice that the 10% discount doesn't get carried through to the Cart Page