Sales system, sales management terminal and program for selling goods aboard train

A user mobile terminal uses an in-train merchandise purchase program to have ordering information entered. A merchandise management terminal in the train receives that ordering information and, if the payment method is cash payment, transfers the ordering information to a salesperson terminal. The merchandise management terminal discerns the payment method from the ordering information and, if the payment method is any othermethodthancashpayment, requests a merchandise management server 7 for authentication and, if authentication is given, transfers the ordering information to the salesperson terminal. The merchandise management server, having received a notice of sale completion from the salesperson terminal via the merchandise management terminal, settles the account with a passenger requiring any other payment method than cash payment.