The rules are below, and there is no need to register.

Double points when you dine

1. Double points when you spend £15 or more at airside catering oulets at Heathrow. Offer excludes Eurest outlets.
2. Offer valid from 4 May 2015 to 31 May 2015 inclusive.
3. Extra points will be awarded on transaction value only, member status does not apply.
4. Heathrow Rewards card must be presented at time of transaction.
5. Only one offer per transaction.
6. Points will be deducted from accounts if items are subsequently returned.
7. Heathrow Rewards programme terms and conditions apply.