A system and method for verifying the authenticity and payment of a bank check at any of a plurality of banks or check cashing sites, wherein a payor or issuing site determines a first set of data including account and individualized payee data, which is communicated to a processing center for temporary storage and eventual comparison. Upon presentation of the check for redemption, the cashing site will establish a second set of data at least including the pre-printed account data and, depending on the embodiment, the individualized payee data that appears on the face of the check when presented. The second set of data is communicated to the processing center where the first and second sets of data are compared. Subsequent to comparison, authenticating data will be communicated to the cashing site, which is indicative of redemption authorization or refusal. Additional embodiments include assuring payment for and delivery of merchandise associated with an Internet commercial transaction.