Retailers in the US are taking the lead in testing a new biometric payment system, called Pay By Touch.

Convenience stores, gas stations, and supermarket chains in the Carolinas, Virginia, Florida, and Illinois are amongst the first to install the system, which works by scanning an index finger to identify the user and allow him or her to pay with his debit card.

Pay By Touch says that the fingerprint image is not the same as that used by the government to identify people. Rather, it uses point-to-point measurements of both index fingers, so that either can be used to pay.

An account is created in-story with a blank check and a driver's license for positive ID. Applications can also be done online, where the user is assigned a PIN number to be used the first time a purchase is made.

The system is popular with retailers because it doesn't charge the stores the 2 to 3 per cent transaction fees like many banks and credit cards do.