GLOSSARY
Commercial Mail Receiving Agency (CMRA)
By Justin Winter · Updated August 28, 2026
A private business, such as a mailbox rental store, authorized by USPS to receive mail on behalf of customers at a street address rather than a PO Box.
A CMRA is a private mailbox provider — the kind of store that rents street-address mailboxes — operating under a USPS agreement that requires it to verify each customer's identity on Form 1583 before accepting mail for them.
Mail addressed to a CMRA box is typically formatted with a "#" or suite-style unit number rather than "PO Box," which is part of how it is distinguished from a USPS-owned box at a post office.
See also
- Secondary address unit designator — The abbreviation USPS uses for a unit within a building — Apt, Ste, Unit, Fl — placed after the street address to route mail within a multi-unit property.
Back to the full mail glossary.