Guides

CMRA compliance for mailbox rentals

Sources checked 31 October 2026. General information, not legal advice: rules and program terms change, so confirm with the carrier or your postmaster before you rely on them.

A store that rents mailboxes and accepts mail for its box holders is a Commercial Mail Receiving Agency (CMRA), and the USPS rules for CMRAs are in section 1.8 of the Domestic Mail Manual, chapter 508. They were rewritten in 2023 and clarified in 2024. This guide sets out what they ask of the store, in the order a store meets them.

1. What counts as a CMRA

The DMM defines a CMRA as a business that accepts delivery of mail on behalf of another person or business, in whole or in part. Businesses whose main service is office space, or reshipping and redelivery, are treated as CMRAs too.

2. Register the store: PS Form 1583-A

• The owner or manager files PS Form 1583-A with the postmaster responsible for the store’s delivery address, and presents a current primary and secondary ID.
• The postmaster verifies the owner’s home address on the form, witnesses the signature, signs the form, and gives the owner a copy of the CMRA regulations.
• Any change to the information on file needs a new application. False or withheld information is grounds for denial.

3. Sign up each box holder: PS Form 1583

• One form per person. Each addressee completes and signs a separate PS Form 1583; spouses each sign their own.
• Two current IDs. Both must be unexpired and traceable to the applicant. If the information on the application does not match the IDs, the CMRA must deny it.
• Witnessing. Since the 2024 clarification, the applicant may sign in the physical or virtual (real-time audio and video) presence of the CMRA owner, manager or an authorized employee, or acknowledge the signature before a notary commissioned in a US state or territory, in person or virtually. USPS did not prescribe how a virtual session must be conducted or recorded.

4. Enter every form in the USPS registration database

The 2023 rule moved CMRA records online. The CMRA must enter the information from each PS Form 1583 and upload a clear copy of each ID document into the USPS CMRA Customer Registration Database, which the owner or manager reaches through a USPS Business Customer Gateway account. The DMM says ID images need not be kept at the store once they are uploaded, and that the store keeps a copy of each PS Form 1583 available for inspection.

5. Certify every quarter

By 15 January, 15 April, 15 July and 15 October, the CMRA certifies in the database that every PS Form 1583 is current, that termination dates are entered and that no ID has expired. Expired, illegible or unclear documents count as noncompliance. A CMRA that does not comply after written notice can have delivery suspended.

6. Address mail with the box number

Box holders’ mail must carry the box number as “PMB” or the “#” sign followed by the number. The preferred form puts it on its own line:

JANE DOE
PMB 123
100 MAIN ST
SPRINGFIELD, ST 00000

If the store’s own address already has a suite or unit, box holders must use this separate “PMB” line rather than combining the two. Mail without the box number can be returned as undeliverable.

7. When a box holder leaves

• Neither the box holder nor the store files a change of address with USPS.
• The store records the termination date on its copy of PS Form 1583, enters it in the database, and keeps the endorsed forms for at least six months.
• For at least six months the store remails the former box holder’s mail, with new postage, to the address they leave, unless the box holder waives that in writing.
• After six months the store returns certain classes of mail, such as First-Class Mail and Priority Mail, endorsed as having no authorization to receive mail for that addressee.

Where software fits, and where it does not

USPS publishes no API or file upload for the registration database: each PS Form 1583 is entered by the store in the USPS web application. No point-of-sale or mailbox software can file it for you, Pack and Kin Studio included. What software can do is keep the rest straight. On the Pack and Kin Studio free plan that means box rentals and renewals, authorized recipients, inbound package logging, holder notifications, pickup records with signatures and CMRA box-holder reporting, so the store knows which boxes opened, closed or changed before each quarterly certification.

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