A payment-enabled mobile device receives, during a first tap of the mobile device on a proximity reader component of a point of sale (POS) terminal, first transaction context data for a current transaction, and receives during a second tap of the mobile device on the proximity reader component, second transaction context data for the current transaction. When the mobile device determines that the second tap is for the same transaction as the first tap, and that one of a customer verification method (CVM) status or a user acknowledgment status flag has been set, then it transmits a payment card account number to the POS terminal to consummate the transaction.