The invention relates to a transaction method comprising the steps of: during a
payment transaction between a customer and a merchant (ML1), establishing a
communication link between a
payment terminal (TP1) of the merchant and a mobile terminal (MT1) of the customer; acquiring, via the
payment terminal (TP1), a payment device identifier (CI1); transmitting
transaction data to a
server (PSRV); transmitting, via the
server, to the customer's terminal an access link (PNLK) to an application (WP); upon activation of the access link, transmitting, via the mobile terminal, to the
server, an access request to the application containing the access link and the payment device identifier; upon
receipt of the access request, generating and transmitting, via the server, a progressive
web application to the mobile terminal; and receiving and executing the application via the mobile terminal. Figure 2