Originally Posted by stifle

Debit cards will mostly work, but banks have the option to disable payments by their cards when online authorisation isn't possible, such as on a plane. This setting is card by card and normally used for customers who are considered a poor credit risk such as those issued for basic bank accounts. Any such cards will not be able to be used on board. Nor, in all likelihood, will Apple Pay be accepted even when contactless starts to work.