A PO Box is a locked box inside a Post Office, and USPS is the carrier that delivers to it. For a seller that settles two questions. Ship a buyer’s “PO Box 123” order with a USPS label. And if you rent a box to keep your home address off your packages, ask for Street Addressing so private-carrier returns can reach it.

Both halves are covered here, with the rules taken from USPS’s own pages.

A buyer gives you a PO Box address

Use a USPS service

A plain PO Box address has no street, and the box sits behind a Post Office counter. USPS Ground Advantage, Priority Mail and Priority Mail Express all deliver there. USPS’s rules provide for private-carrier packages at a PO Box only when the holder has signed up for Street Addressing and gives you the street-style version of the address (more on that below). If the address line says “PO Box”, choose a USPS rate.

The package does not have to fit in the box

USPS’s PO Box page explains what happens to a parcel that is too big for the box: the holder either gets a slip to collect it at the counter during business hours, or picks it up from a secure parcel locker. The ordinary USPS limits still apply: 70 lb, and a combined length and girth of 108 inches for Priority Mail and Priority Mail Express or 130 inches for USPS Ground Advantage (DMM 101, section 3.2; USPS, preparing packages).

For a sense of scale, USPS lists five box sizes, most of them 14.75 inches deep:

USPS PO Box size Door size What USPS says it holds
XS (Size 1) 3" x 5.5" 10 to 15 letters
S (Size 2) 5" x 5.5" 15 or more letters, or 1 Small Priority Mail Flat Rate Box
M (Size 3) 5.5" x 11" Large envelopes and magazines stacked flat, or 2 Small Flat Rate Boxes
L (Size 4) 11" x 11" Small and Medium Priority Mail Flat Rate Boxes
XL (Size 5) 12" x 22.5" Multiple packages

Two things that work differently for a PO Box delivery

  • Tracking can end at a locker or a counter. A parcel held for the box holder shows a pickup status, not a doorstep delivery. The main site explains Delivered to Parcel Locker and Available for Pickup, which are worth sending to a buyer who asks where the package is.
  • You cannot redirect a package to a PO Box. USPS Package Intercept lists items redirected to a PO Box as not eligible. If a buyer asks you to reroute a shipment to their box after it has left, the answer is no.

A PO Box is also one of the more secure places a package can land, since it stays inside the Post Office until the holder collects it. For a buyer worried about porch theft, it is a reasonable address to suggest. See Package Theft: What a Seller Can Do.

Renting a PO Box for your own shop

The usual reason a home seller rents a box is the return address. Every label you print shows where the package came from, and a PO Box keeps your home address off thousands of doorsteps.

What it takes to open one

From the USPS PO Box page, as of October 12, 2026:

  • Terms of 3, 6 or 12 months, paid in full up front. A 3 month term requires automatic renewal; 6 and 12 month terms let you opt out.
  • Two forms of acceptable U.S. identification, shown at the Post Office where the box is located within 30 days of applying online.
  • Two keys or a lock combination once you are verified.
  • Payment by the 10th of the month it is due. USPS closes the box on the 11th otherwise.
  • A partial refund if you close the box early, based on how long you have had it.

Prices depend on the location and the box size. USPS publishes them by fee group in Notice 123 and through a lookup on the PO Box page, so check the specific Post Office before budgeting. Not every size is available at every location.

Street Addressing: the option sellers should ask about

A plain PO Box address is a USPS-only address. Returns do not always come back by USPS: a buyer may use a prepaid label from a private carrier, and a supplier may ship stock that way.

Street Addressing solves this where the Post Office offers it. Under DMM 508.4.5.4, a customer who signs the agreement may use the Post Office’s street address with the box number after a # sign, in the form “123 Main Street #4567”, and may receive packages from private carriers at that address. USPS’s page names UPS, FedEx, DHL and Amazon, “as long as they comply with USPS mailing standards”, which includes the 70 lb and 130 inch limits. The service is subject to availability and restrictions, so confirm it at the counter before you print a new return address on anything.

Signature on File

Insured and signature-required items normally mean a trip to the counter. With Signature on File, USPS keeps your signature and leaves those items in your box or a parcel locker. DMM 508 lists Priority Mail Express, insured mail over $500 and Signature Confirmation items as covered. USPS describes the service as free.

The honest drawbacks

  • You have to go and get it. Nothing arrives at your door. If the Post Office is a 25 minute drive, returns will sit.
  • Large inbound parcels wait at the counter, which is open only during business hours, unless your location has parcel lockers.
  • A plain PO Box is a USPS address. USPS provides for private-carrier packages only through Street Addressing, so without it a return sent by another carrier may not reach you.
  • Mail scans need the right account. Informed Delivery, the free USPS preview of incoming mail and packages, covers PO Box addresses, but USPS requires a USPS.com business account for them.

A quick decision

Your situation A PO Box is
You ship from home and do not want your address on labels Worth it, with Street Addressing if offered
Your returns come back by more than one carrier Only workable with Street Addressing
You receive bulky stock deliveries A poor fit; packages over 70 lb, or over 130 inches on USPS Ground Advantage and 108 inches on other services, cannot be accepted
The nearest Post Office is far away or has short hours Likely more trouble than it saves

Sources

Checked October 12, 2026 against the USPS PO Boxes page, DMM 508, Recipient Services (section 4.0), Notice 123 (prices effective October 4, 2026), and the USPS pages on Package Intercept, Informed Delivery and preparing packages. Availability of sizes, Street Addressing and parcel lockers varies by Post Office.