In a purchase transaction between a merchant and a customer, a merchant device sends transaction information to a payment gateway and sends a beacon signal containing a transaction identifier to a customer mobile device. The customer mobile device sends the transaction identifier and payment information corresponding to a customer payment account to the payment gateway. The payment gateway applies the transaction identifier to access the transaction information received from the merchant device and sends purchase information based on the transaction information to the customer mobile device. The customer mobile device displays the purchase information to the customer, obtains an indication of customer assent to pay for the item and sends a confirmation of customer assent to the payment gateway. Upon receiving the confirmation of customer assent from the customer mobile device, the payment gateway Processes the purchase transaction based on the payment account information.