The bank has given the fob to 250 customers as part of a three-month national trial.

The fob features a small fingerprint reader so it can’t be used by anybody else if it gets lost.

It can be kept on a keyring and can be used at existing contactless and chip and pin terminals.

The £100 limit is an increase on the current £30 contactless limit.

The bank has previously piloted biometric debit and credit cards.

NatWest is working with Visa and Giesecke+Devrient Mobile Security to bring the service to customers in the UK.

David Crawford, head of NatWest effortless payments, said: “After the successful pilot of our biometric debit card we are looking at how we can further develop the technology and push the boundaries to integrate it into our customers everyday lives.”

Jeni Mundy, managing director, UK & Ireland, at Visa, said: “Following the launch of the UK’s first biometric debit card earlier this year, we are again pleased to collaborate with NatWest on this pilot.

“Our research tells us that people have a strong interest in biometric technologies which can make their lives easier as well as increasing the security of their payments. At Visa we are constantly looking for ways to innovate with our partners to give consumers greater choices in how they pay.”