Abstract: A system for ordering and purchasing food utilizing a patron device at a restaurant includes a staff device and an order server. The order server creates an order and a code identifying the order. The code is sent to the staff device where it is displayed. The patron device scans and sends the code to the order server, which determines whether the received code matches a still-active order. When yes, the order server stores an association of the patron device with the order and adds to the order food items specified messages received from the patron device. The patron device may thereafter be trusted and utilized to add subsequent patron devices to the order in a similar manner without involvement of the staff device. The order server tracks food items ordered and presents a billing screen on each device with only items ordered on each device preselected for payment.