A shopping support device includes a memory, a reading device, a network interface, and a processor. The processor is configured to, upon reading of a first code with the reading device at a store, decode the first code and acquire and, then store in the memory, first and second parameter values, and then control the network interface to connect to a store network using the first parameter value. Upon the reading of a commodity ID for a commodity with the reading device, the commodity ID is transmitted to a store server via the store network for registration. Upon receipt of a request from a user, checkout processing is performed based on the registered commodity ID on the server and the second parameter value.