In the UK, folks making contactless (NFC) card payments at stores and supermarkets are limited on how much they can ring up at the checkouts. But for a few NatWest customers that limit is set to disappear, as the bank launches a trial for using biometric authentication when making card payments.

As in other countries around the world, many stores, service stations and eateries in the UK now cater for contactless payments by card, where a customer waves a chipped card over the top of a reader until a beep sounds and payment is made without having to enter a security code. Such transactions are limited to £30 a pop for security reasons.

NatWest has teamed up with digital security company Gemalto, along with Visa and Mastercard, to trial a card that scans a user's fingerprint to verify identity, and then unlocks the per transaction limit that's normally applied.

"Using a fingerprint rather than a PIN code to authorize transactions has many advantages, primarily enhanced security and greater convenience," said Gemalto's Howard Berg. "Cardholders can pay quickly and easily with just a simple touch, and they no longer need to worry about the limit on contactless payment transactions."

A user's registered fingerprint is stored on the card itself and verification takes place directly on the card too, so retailers won't need to update their point-of-sale technology. The card can be set up at a branch or at home, the latter involving bank customers being sent a special sleeve with their card. Once a fingerprint has been added to a card, it can't be changed.

The fingerprint-sensing card trial is due to start in the coming weeks, with NatWest choosing 200 of its customers to take part. The video below gives an idea of how the system might work.