A method and associated terminal, server, and system for information registration, especially payment account registration processes involving payment transactions, are disclosed. By scanning tangible information carriers such as a driver license and credit cards, a client terminal such as a smart phone can generate an image that is sent to a registration server. The registration server can extract user identity information and payment account information from the image. After verifying that the user identity information is associated with a payment account, the registration server generates a registration code for the user and sends the registration code to the client terminal and a bank server. The bank server can then establish corresponding relationships between the registration code, a terminal identifier for the client terminal, and the payment account so that later payment requests from the client terminal can be processed more efficiently and securely.