A checkout system, comprising: a mobile point-of-sale (POS) apparatus including: a beacon receiver ; an operation panel ; a wireless communication interface ; a code reader ; and a processor configured to control the wireless communication interface to transmit a first signal indicating that a particular user operation has been performed on the operation panel and a second signal indicating that the beacon receiver is receiving a beacon signal; and a server communicably connectable to the mobile POS apparatus characterized in that the particular user operation as indicated by transmission of the first signal is a request for a user checkout operation, and the server is configured to perform the user checkout operation upon receiving the first signal while the second signal is being received, the processor is further configured to control the wireless communication interface to transmit a third signal indicating a user selection on the operation panel to continue product registration, the server is configured to disable performance of the user checkout operation for a predetermined period of time after the third signal is received; the processor is configured to control the wireless communication interface to transmit a fourth signal indicating a predetermined code has been read by the code reader after the predetermined code is read by the code reader , and the server is configured to permit performance of the user checkout operation upon receiving the fourth signal. a mobile point-of-sale (POS) apparatus including: a beacon receiver ; an operation panel ; a wireless communication interface ; a code reader ; and a processor configured to control the wireless communication interface to transmit a first signal indicating that a particular user operation has been performed on the operation panel and a second signal indicating that the beacon receiver is receiving a beacon signal; and a beacon receiver ; an operation panel ; a wireless communication interface ; a code reader ; and a processor configured to control the wireless communication interface to transmit a first signal indicating that a particular user operation has been performed on the operation panel and a second signal indicating that the beacon receiver is receiving a beacon signal; and a server communicably connectable to the mobile POS apparatus characterized in that the particular user operation as indicated by transmission of the first signal is a request for a user checkout operation, and the server is configured to perform the user checkout operation upon receiving the first signal while the second signal is being received, the processor is further configured to control the wireless communication interface to transmit a third signal indicating a user selection on the operation panel to continue product registration, the server is configured to disable performance of the user checkout operation for a predetermined period of time after the third signal is received; the processor is configured to control the wireless communication interface to transmit a fourth signal indicating a predetermined code has been read by the code reader after the predetermined code is read by the code reader , and the server is configured to permit performance of the user checkout operation upon receiving the fourth signal. <EOS>