Method of using a user device for remote payment of a shopping basket on a merchant server, and an associated system

A method of using a user device for remote payment of a shopping basket on a merchant server, said user device being configured to connect to a mobile telephony network and being associated with an identification number in said mobile telephony network, wherein:

• a) the user device selects a method of paying for the shopping basket on a first page of the merchant server;
• b) on the method of payment being selected, the user device sends a payment request to a payment validation module, said request being automatically enriched with identification data of the user device from which it is possible to determine the identification number of said user device in the mobile telephony network;
• c) the user device receives a local authentication request message from the payment validation module that is sent over the mobile telephony network to the identification number of the device in the mobile telephony network;
• d) on receiving the local authentication request message, the user device automatically triggers execution of an operation of locally authenticating a user of the user device;
• e) the user device sends a local authentication response message to the payment validation module;
• and
• f) the user device is redirected by the payment validation module to a second page of the merchant server giving the result of the payment transaction.