A customer computer receives, through radio communication, from a computer of a product or service provider (a provider), items of personal information necessary for member registration. Then, the customer computer extracts, from a storage device storing personal information for the customer in advance, customer personal information corresponding to the items of personal information received from the computer of the provider, and transmits the extracted personal information to the computer of the provider. Thereafter, the customer computer receives, from the computer of the provider, member identification information and stores the member identification information. Therefore, customer can transmit/register personal information to a product or service provider, without repeatedly writing or entering the same data. The storage device of the customer computer stores member identification information, so the customer does not have to carry a number of different point cards that were respectively issued for use at the stores.