Mobile commerce authentication and authorization systems

Mobile commerce authentication and authorization systems enable currently existing point-of-sale devices that are neither structurally nor systemically altered to conduct financial transactions with a customer using an access terminal across a wireless communications system. The point-of-sale devices receive an input from a payment instrument replacement, which identifies the transaction to the point-of-sale device as a transaction including an access terminal. Authentication of the user of the access terminal is achieved at least by application of position and/or location determinable features of the access terminal, the position and/or location of a point-of-sale device of a vendor or merchant where the customer seeks to purchase goods or services, and the payment sum entered on the point-of-sale device. A payment matching server may assist in processing the location data and the payment sum amount across communications network.