A server to process a tab for a customer at a merchant premises may provide a list of candidate merchant premises to a customer mobile device, receive a signal indicating a user selection of one of the candidate merchant premises, receive payment card details for the customer mobile device, obtain a specific code for a tab at the selected merchant premises, send to the customer mobile device the specific code, receive a signal from a Point of Sale (POS) terminal of the selected merchant premises, associate the customer mobile device with an open tab maintained by the POS terminal, receive from the POS terminal at least one identifier and amount for each purchase of the open tab, request payment of at least a portion of a balance of the open tab from a payment gateway using the payment card details, and notify the POS terminal of the payment.