What is a CMRA? The plain-English guide for shop owners
Private mailboxes, plain English. Here is what the USPS paperwork is for.
Last updated: November 2026
What a CMRA is 📬
A Commercial Mail Receiving Agency receives mail for other people or businesses. Private mailbox stores and virtual mailbox providers are common examples. A CMRA is not a USPS Post Office.
How to register as a CMRA
- Give PS Form 1583-A, Application to Act as a Commercial Mail Receiving Agency, to your local Postmaster. This is for the business, not for each mailbox renter.
- Create or sign in to your USPS Business Customer Gateway account.
- Find CMRA service access for your business location and request the administrator role.
- Request the administrator code. The mailed code generally arrives within about 10 business days. It expires 25 days after the request, not 25 days after delivery. Enter it as soon as it arrives.
- Once access is approved, add each mailbox customer and upload their signed Form 1583 and accepted IDs.
- Maintain your customer records and complete quarterly certification.
PS Form 1583-A vs PS Form 1583
1583-A: the business applies to act as a CMRA.
1583: each applicant authorizes the CMRA to receive mail on their behalf. Download the free fillable customer form
Rules for renting private mailboxes
- Verify acceptable photo and address IDs. Utility bills are not on the accepted address-ID list.
- Use “PMB” or “#” with the box number. For example: 123 Main St PMB 234.
- Have signatures witnessed by the CMRA in person or by live audio/video, or acknowledged before a U.S. notary.
- Keep customer details current and complete quarterly certification by January 15, April 15, July 15 and October 15.
What to keep on file and for how long
Keep the signed Form 1583 throughout the rental and for at least six months after termination. Keep a digital copy at the store, available to USPS representatives. Uploaded ID images do not have to be retained at the CMRA. Read the USPS rules
Good questions 📬
Can I use a utility bill as the address ID?
No. Choose an accepted address ID, such as a lease, mortgage, voter or vehicle registration, or home or vehicle insurance policy.
Who uploads the renter’s form?
The CMRA. See the upload guide
Does software replace CMRA registration?
No. Your store still needs to complete USPS registration and follow the rules.
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