The contactless facility is nothing to do with debit/credit. We have separate debit cards and credit cards here. The card you hand over dictates whether the money comes straight out of your bank account (debit) or is a credit payment (where you borrow the money and pay it back later with/without interest). Put simply, you can use your card contactlessly as long as it has a particular logo on (almost all do) and the card reader can take contactless payments. You just hold the card about 0.5cm from the reader, the machine beeps and that's it. You've paid. With a debit card, the money leaves your account within between 1 second and 24 hours depending on your bank. I have the ability to pay contactlessly on my debit card and both of my credit cards. It's simply a way to pay quickly, without having to remember your PIN. As a security measure, each bank sets a random interval after which the machine will automatically ask for the PIN, to check the rightful holder is using it.