Method for carrying out a financial transaction with a Merchant Terminal, method implemented within a terminal of a user wishing to carry out a transaction with a merchant, the method being processed the terminal of the user and characterized in that it comprises: - a step for receiving a merchant's identifier (IdM): - by reading a barcode with a camera of the terminal of the user; or - By receiving a message thru a Bluetooth interface of the terminal of the user; or - By receiving a message thru a contactless interface of the terminal; or - By receiving, from a remote server, a piece of data representing the merchant's identifier; - a step for receiving a piece of data representing a transaction amount (Px), comprising: - reading a barcode with a camera of the terminal of the user; or - receiving a message thru a Bluetooth interface of the terminal of the user; or - receiving, from a remote server, a piece of data representing the transaction amount; - a step for generating a transaction, by means of the user's terminal, for said merchant comprising: - obtaining location data of said user's terminal with a GPS or a mobile network; - creating a record comprising the merchant's identifier, the piece of data representing the transaction amount, a piece of data representing an identifier of the user, location data of said user's terminal; - a step for transmitting said transaction to a transaction management server (Srv), for processing the transaction with the merchant's terminal on a bank account of the user, in which said transaction management server to which the transaction is transmitted checks the validity of the transaction with a database, maintained by the transaction management server (Srv), comprising a piece of data representing the transaction amount and an identification of a selling location; - a step for receiving at least one assertion of validation of the transaction transmitted by the transaction management server (Srv), after it has checked the validity of the transaction and processed the transaction. - a step for receiving a merchant's identifier (IdM): - by reading a barcode with a camera of the terminal of the user; or - By receiving a message thru a Bluetooth interface of the terminal of the user; or - By receiving a message thru a contactless interface of the terminal; or - By receiving, from a remote server, a piece of data representing the merchant's identifier; - by reading a barcode with a camera of the terminal of the user; or - By receiving a message thru a Bluetooth interface of the terminal of the user; or - By receiving a message thru a contactless interface of the terminal; or - By receiving, from a remote server, a piece of data representing the merchant's identifier; - a step for receiving a piece of data representing a transaction amount (Px), comprising: - reading a barcode with a camera of the terminal of the user; or - receiving a message thru a Bluetooth interface of the terminal of the user; or - receiving, from a remote server, a piece of data representing the transaction amount; - reading a barcode with a camera of the terminal of the user; or - receiving a message thru a Bluetooth interface of the terminal of the user; or - receiving, from a remote server, a piece of data representing the transaction amount; - a step for generating a transaction, by means of the user's terminal, for said merchant comprising: - obtaining location data of said user's terminal with a GPS or a mobile network; - creating a record comprising the merchant's identifier, the piece of data representing the transaction amount, a piece of data representing an identifier of the user, location data of said user's terminal; - obtaining location data of said user's terminal with a GPS or a mobile network; - creating a record comprising the merchant's identifier, the piece of data representing the transaction amount, a piece of data representing an identifier of the user, location data of said user's terminal; - a step for transmitting said transaction to a transaction management server (Srv), for processing the transaction with the merchant's terminal on a bank account of the user, in which said transaction management server to which the transaction is transmitted checks the validity of the transaction with a database, maintained by the transaction management server (Srv), comprising a piece of data representing the transaction amount and an identification of a selling location; - a step for receiving at least one assertion of validation of the transaction transmitted by the transaction management server (Srv), after it has checked the validity of the transaction and processed the transaction.