Abstract: A mobile phone payment method and system in which a mobile phone, a photo receiver, and a control server for storing payment-related information of a user of the mobile phone, download the payment-related information of the user from the control server to the mobile phone. The payment-related information is converted into binary code data. A light signal from a backlight of the mobile phone, based on the binary code data, is transmitted to the photo receiver. The photo receiver authenticates the binary data from the received light signal and authorizes payment accordingly.