Implementation manners of the present invention disclose a data processing method and system, a terminal, and a server, where the data processing method includes: acquiring a service processing instruction inputted by a user; generating a service processing request according to the service processing instruction, where the service processing request includes a unique identifier of the terminal; and sending the service processing request to a server, so that the server queries, according to the unique identifier of the terminal in the service processing request, an on-sale data maintenance list for product information corresponding to the unique identifier of the terminal; and processing, according to the product information corresponding to the unique identifier of the terminal, a service requested by the service processing request. The technical solutions disclosed by the present invention require no complex manual operations, thereby decreasing an error rate, improving a service processing speed.