Auxiliary On-Us Field

A field on the magnetic ink character recognition (MICR) line of a check or share draft. This is an optional field that can be found to the left of the routing number. The presence of this field makes the check in-eligible to be used as a source document for accounts receivable conversion (ARC), back office conversion (BOC), and point-of-purchase (POP) entries.

Related Terms

  • Regulation E (Reg-E)

    Regulation E details procedures for the processing of electronic funds transfers (EFTs) in addition to debit cards.

    Learn More
  • SSL (Secure Sockets Layer)

    SSL, proceeded by TLS, is a security protocol that encrypts data and enabled authentication between applications over a network.

    Learn More