The invention relates to a method for processing transactional data, implemented within a secured intermediate server, connected to a communications network. Such a method comprises: reception, by the secured intermediate server, of a request for payment comprising a piece of data representing an identification of a communications terminal used by a user to carry out a purchase operation with a merchant server connected to said communications network; setting up a secured point-to-point link with a payment module of the communications terminal; transmission, to said payment module, of a request for execution of payment; reception, by the payment module, of a piece of information on payment; transmission of a message of information to the merchant server.