How to Start a PO Box Business: CMRA Registration and Requirements

To start a PO Box business, you register with the United States Postal Service as a Commercial Mail Receiving Agency (CMRA) by filing PS Form 1583-A in person at your local post office, then equip a commercial location with secure mailbox units and a customer identity-verification system built around PS Form 1583. One thing to know at the outset: you will not actually be renting out PO Boxes. Those belong to the USPS and sit inside post offices. What you rent are Private Mailboxes (PMBs), and every customer address must include “PMB” or the “#” symbol before the box number under the Domestic Mail Manual.¹

A CMRA is any business that accepts delivery of U.S. Mail on behalf of another person as a commercial service. That covers everything from first-class letters to packages, and it puts you in an agent relationship between the postal carrier and your customer. The upside for your customers is that a PMB address looks like a regular street address and can also receive packages from FedEx, UPS, and other private carriers, which a PO Box cannot.

Register as a CMRA With PS Form 1583-A

Every CMRA must register with the post office that delivers mail to its address. The registration form is PS Form 1583-A, “Application to Act as a Commercial Mail Receiving Agency,” available on usps.com or at any post office.²

The form asks for your business’s full legal name, the exact commercial address where mail will be received, and the names and home addresses of every owner, officer, or partner. If any of that information changes, you file a new application.³

You cannot mail the form in. The owner or manager must appear in person at the post office with two current, unexpired forms of identification. The Postmaster or designee verifies that you reside at the home address on the form, witnesses your signature, and countersigns the application.³ The post office keeps the original, scans it into the USPS Facilities Database, and gives you a copy. There is no federal fee.

Get this right the first time. False information on a federal form violates 18 U.S.C. § 1001, which carries fines and up to five years of imprisonment.⁴

If the Postmaster Denies Your Application

You have 30 days to submit a written appeal to the Pricing and Classification Service Center, which issues the final decision.⁵

What Happens After Approval

Expect an on-site visit from the Postal Inspection Service. Inspectors look at the mailbox units, the sorting area, and how you store customer identification records. Passing that inspection is what allows you to legally begin accepting mail for customers.

Set Up the Physical Facility

Your CMRA has to operate from a commercial location that complies with local zoning for mail and parcel handling. A residential property will not qualify. You need a storefront or commercial suite with room for foot traffic, secure storage, and a separate sorting area.

The core hardware is the mailbox units themselves, sometimes called nests. These are reinforced aluminum or steel compartments, each with its own lock. Small wall-mounted units with a handful of boxes run a few hundred dollars. Larger pedestal-mounted cluster units with dozens of compartments can cost over $2,000 per section. Size your initial capacity to the market you are targeting and leave room to expand.

The sorting area needs to be physically separated from the public lobby so only authorized employees handle incoming mail before it reaches individual compartments. You also need a secure zone for oversized parcels that will not fit in standard boxes. Packages sitting in an open area invite theft and will be flagged by a federal inspector.

The USPS recommends video cameras inside and outside the building, sign-in sheets for anyone entering the mail area, and card readers or badge systems for employee access.⁶ These are best practices rather than strict mandates, but having them in place before your first inspection matters.

Verify Every Customer With PS Form 1583

Every person or business renting a mailbox must complete PS Form 1583, “Application for Delivery of Mail Through Agent.” This is what legally authorizes you to accept mail on their behalf. You collect it, verify identity, and keep the form on file for the life of the account.⁷

The identity check requires two documents. The first must be a government-issued photo ID. Acceptable options include:

A state driver’s license or non-driver ID card
A U.S. passport or foreign passport
A uniformed services ID card
A U.S. permanent resident card
A certificate of naturalization
A NEXUS card or Matricula Consular

Social security cards, birth certificates, and credit cards do not qualify as primary identification.⁷

The second document must confirm the customer’s current physical address. Acceptable options include a current lease, a mortgage or deed of trust, a home or vehicle insurance policy, a vehicle registration card, or a voter registration card. The address on this second ID must match the home or business address the customer listed on the form. Utility bills and bank statements are not accepted.⁷

You must physically inspect the originals. Keep copies of both IDs in the customer’s file. These records must be available at all times for examination by the Postmaster or the Postal Inspection Service.⁷

If you fail to collect and maintain these forms properly, the USPS can withhold all mail delivery to your entire facility, not just the noncompliant customer’s box. That one enforcement lever can shut you down overnight, which is why experienced operators treat the 1583 file as the most important thing in the office.⁷

Remote and Virtual Customers

If you offer virtual mailbox services where customers sign up online, the identity verification requirement does not relax. The customer must sign or confirm their signature either in your physical presence or through a real-time audio and video connection with you or your authorized employee. Alternatively, they can acknowledge their signature in real-time audio and video before a notary public commissioned in a U.S. state or territory.⁷ There is no option to have the customer sign the form alone and mail it in.

Business and Organization Applicants

When a corporation, LLC, or other entity rents a box, an officer signs the PS Form 1583 and provides their title. That officer goes through the same two-ID verification. Every additional person authorized to receive mail at the box must be listed on the form and be prepared to present two valid IDs to the Postal Service on request.⁷

The CMRA Customer Registration Database

The USPS requires CMRAs to enter customer data from each PS Form 1583 into an electronic system called the CMRA Customer Registration Database and to upload copies of the supporting identification documents.⁸ Paper-only record keeping is not enough.

For new customers, the entry has to happen when the application is received. No grace period. You also keep at least a digital copy of each completed PS Form 1583 at your business location, available for inspection at any time.⁹ Once a customer’s account closes, you retain their records for at least six months after the termination date.⁸

Quarterly Certification Keeps the Business Open

Registration is not one-and-done. Every quarter, you certify in the database that all PS Forms 1583 are current, all termination dates are updated, and no customer IDs have expired. Certifications are due January 15, April 15, July 15, and October 15.⁸

This is where operators get caught. A customer’s driver’s license expires, nobody notices, and the quarterly certification comes due, or an inspector shows up first. Build a system that flags expiring IDs a month ahead. The penalty for noncompliance is not a fine. The USPS withholds all mail delivery to your agency, and if the problem is not corrected within 30 days, the Postal Service may terminate your authorization to operate as a CMRA entirely.⁸

Forwarding Mail After a Customer Leaves

When a customer cancels or you terminate the relationship, neither party files a change-of-address order. You are responsible for remailing any mail that continues to arrive for that customer for at least six months after termination, and the postage comes out of your pocket.¹⁰

The customer can waive that obligation with written instructions telling you not to remail some or all of their mail. Those instructions cannot direct you to refuse the mail, return it to the sender, or hold it during the six-month period and then dump it at the post office.¹⁰

After the six months end, you may return certain classes of mail (First-Class, Priority, Priority Mail Express, USPS Ground Advantage Retail, and accountable mail) to the post office without new postage. Each piece must be endorsed: “Undeliverable, Commercial Mail Receiving Agency, No Authorization to Receive Mail for this Addressee.” You hand it to the post office directly; a collection box will not do.¹⁰

Factor this into your pricing. High turnover means real postage costs. Some operators build a forwarding deposit into the rental agreement.

Suspicious Mail and Where Your Liability Sits

The USPS prohibits certain items from the mail entirely, including explosives, ammunition, liquid mercury, and other hazardous materials, with civil penalties from $250 to $100,000 per violation plus potential criminal charges.¹¹

If something suspicious arrives, the Postal Inspection Service advises isolating the item, documenting its visible surfaces if you can do so safely, keeping a safe distance, and calling Postal Inspectors at 1-877-876-2455.¹²

Once the carrier delivers mail to your facility, the Postal Service considers it delivered. Any lost, misplaced, or stolen items after that point are between you and your customer. The USPS directs customers to contact the CMRA directly, not the Postal Service, for facility-level delivery problems.¹³ Carry general liability insurance and use a rental agreement that clearly defines what you are and are not responsible for.

Startup Costs and Revenue

The federal registration itself is free. Your real expenses come from everything around it:

Commercial lease. Rent varies widely by market. You need a storefront or suite in a commercially zoned area with room for mailbox units, sorting, parcel storage, and a customer lobby.
Mailbox units. Small wall-mounted units start around a few hundred dollars. Larger pedestal-mounted or surface-mounted cluster units run roughly $1,200 to $2,100 or more per section. Most new CMRAs need several sections to reach a viable number of boxes.
General liability insurance. Annual premiums for small mail-handling businesses typically fall between $300 and $1,500 depending on location and coverage limits.
Local business licenses. Municipal and county fees generally run $50 to $200 annually for a general retail permit.
Security equipment. Cameras, access controls, and signage. A basic multi-camera system with recording can start under $500.
Ongoing postage for remailing. The six-month forwarding obligation is a recurring operational cost.

Revenue comes from monthly box rentals, typically around $10 for a basic virtual mailing address up to $40 or more for a large physical mailbox. Many CMRAs also earn from package notification fees, mail forwarding, notary services, shipping, and office supplies. Notary services pair naturally with the business since you already need notarization for remote PS Form 1583 verification. State-regulated notary fees generally run $2 to $25 per signature for in-person service, with remote online notarization often permitted at higher rates.

1
USPS Domestic Mail Manual. 508 Recipient Services
2
United States Postal Service. Application to Act as a Commercial Mail Receiving Agency
3
Federal Register. Commercial Mail Receiving Agencies
4
Office of the Law Revision Counsel. 18 USC 1001 – Statements or Entries Generally
5
Postal Explorer. Mailer Compliance and Appeals of Classification Decisions
6
United States Postal Service. Best Practices for Mail Center Security Incoming and Outgoing Operations
7
United States Postal Service. Application for Delivery of Mail Through Agent
8
United States Postal Service. DMM Revision: Commercial Mail Receiving Agencies
9
Federal Register. Commercial Mail Receiving Agencies
10
Postal Explorer. 508 Recipient Services
11
USPS. Domestic Shipping Prohibitions, Restrictions, and HAZMAT
12
United States Postal Inspection Service. Report Suspicious Mail
13
USPS.com. Commercial Mail Receiving Agency (CMRA)