Patent attributes
Described is a technology that enables a customer, who uses a payment card in a transaction and further provides an identifier in the same transaction, to use the identifier as a payment mechanism in all future transactions. In some embodiments, the technology involves communication between a customer's user device, a payment service system (PSS), and one or more merchant POS systems. A merchant POS system collects information in a transaction conducted between the merchant POS system and the customer, including, among others, the customer's contact information (e.g., telephone number), and forwards this information to the PSS. The PSS stores the information as an identifier, where the identifier is stored in association with the card used in the transaction. In a second transaction, the PSS sends a verification request to the user device based on the identifier (e.g., a text message), and processes the transaction only upon confirmation from the customer.