Implementations of the present application provide methods and devices for linking to an account and providing service processing. In one example method, an uncertified server can receive a linking request sent by a terminal device, wherein the linking request corresponds to a user account logged in by a user to the uncertified server. The uncertified service can transmit, to the terminal device, a predetermined instruction based on the linking request, wherein the predetermined instruction instructs the terminal device to send a real service account request to a certified server based on predetermined instruction. The uncertified server can later receive, from the terminal device, a virtual service account identifier generated by the certified server in response to the real service account request sent by the terminal device to the certified server. The virtual service account identifier can then be linked to the user account and used at a later time to transmit service requests along with the virtual service account identifier without sharing the real service account information.