A registration sever receives registration data from a client terminal, wherein the registration data includes user identity information and payment account information, and is generated by the client terminal through scanning one or more tangible information carriers provided by a user and extracting the user identity information and payment account information from one or more images obtained through the scanning. The registration server identifies a bank server based on the payment account information, verifies whether the user identity information is associated with a payment account identified by the payment account information; generates a registration code for the user upon successful verification, sends the registration code to the client terminal; and sends the registration code and a terminal identifier to the bank server, wherein the bank server establishes corresponding relationships between the registration code, the terminal identifier, and the payment account for verifying subsequent payment requests by the client terminal.