Developed by Natural Security - a biometrics specialist owned by banks, retailers and POS giant Ingenico - the system is being tested for six months at sites near Bordeaux and Lille.

The pilot is open to Banque Accord, BNP Paribas, Crédit Agricole and Crédit Mutuel Arkéa customers who first need to visit a branch to register their biometric data in their credit card.

Participants are also given a case - with its own charger - for their card, which facilitates communication between the plastic and the payments terminal.

Once registered, customers who shop at participating outlets can pay by placing their fingers on biometric readers. As long as the card is within one and a half meters of the terminal it can be left in the user's pocket or bag.

The partners are testing two different forms of biometrics during the pilot: digital fingerprints at the Bordeaux site and finger vein patterns at Lille.

Natural Security says that its system offers strong authentication and makes the checkout faster and easier because customers do not need to enter a PIN or even remove their card.

The system also protects user privacy, says CEO Cedric Hozanne: "Natural Security's approach is designed to protect privacy and personal data: the data and applications used for authentication are stored on a personal device (eg smart card, SD card) and remain solely under the user's control. This limits the risk of data misuse and theft."