Patent attributes
A transaction processing system according to various embodiments of the invention is adapted for: (1) associating a particular account (e.g., a credit card account) with a particular phone number; (2) at least partially in response to receiving a request to approve a transaction associated with the account, automatically transmitting a message (e.g., a text message) to the account holder via the phone number, requesting that the account holder confirm that the transaction is valid; and (3) using a response to the message to determine whether to approve or deny the transaction. In various embodiments, the request confirmation message requests that that the user answer a particular question (e.g., regarding out-of-wallet data), and the system is adapted to determine whether to approve or deny the transaction based on whether the response included a correct answer to the question.