A system and method for online payments over the Internet, able to handle several transactions coming from various participants and contributing to a single payment on a merchant's bank account. In many cases, the modifications designed to make a merchant server capable of managing transactions from several participants contributing to a single payment are difficult, even impossible, to carry out since the server's architecture is imposed by the structure of the e-commerce platform used. A server (4), called mirror authorization server, is added and connected to a set typically formed by a customer computer (1), a merchant server (2) and a bank authorization server (3). In particular, the mirror authorization server is used to replace the actual bank authorization server for the purpose of performing certain operations.