How much is a PO Box?
A USPS PO Box costs roughly $60 to over $1,300 per year depending on box size and location. Small boxes run about $5 to $30 per month and medium-to-large boxes about $20 to $70 per month, with 3-, 6-, and 12-month terms available and the 12-month term offering the best value.
Cost breakdown
| Option | Price | Notes |
|---|---|---|
| Size 1 (extra small) | ~$4.50–$36/mo | Holds letters and a few small items |
| Size 3 (medium) | ~$120/yr rural to ~$520/yr metro | Large variation by post office location |
| Size 5 (extra large) | ~$25–$110+/mo | For high mail or small-package volume |
| 3-month term | Highest per-month rate | Most flexible but least economical option |
| 12-month term | Saves ~10–15% vs. quarterly | Lowest effective monthly cost |
How USPS prices PO Boxes
USPS PO Box pricing depends mainly on two things: the size of the box and the location of the post office. Sizes run from Size 1 (extra small) up to Size 5 (extra large), and prices scale up with capacity. Annual costs range from roughly $60 at the low end to more than $1,300 for the largest boxes at the busiest locations.
Location is just as important as size. USPS sorts post offices into pricing groups, and rural or 'market-dominant' offices charge the least, while high-traffic competitive locations in major cities charge premium rates. The same medium (Size 3) box can cost around $120 a year at a rural office or up to roughly $520 a year downtown. A 2.9% price increase took effect January 18, 2026.
Rental terms: 3, 6, or 12 months
When you rent, USPS offers three payment terms: 3 months, 6 months, or 12 months. The 3-month term has the highest effective monthly rate but the most flexibility, which suits short-term or temporary needs. The 6-month term sits in between.
The 12-month term is the most economical, typically saving about 10% to 15% compared with paying quarterly. If you expect to keep the box for a year or more, paying annually is usually the better value. Boxes renew at the start of each term, and you can change box size at renewal if your needs change.
Keys, fees, and getting an exact quote
Most plans include the first two keys. Replacement keys cost about $13 each, and if all keys are lost and the lock must be replaced, the charge is around $27. Some competitive locations waive the initial key deposit, while others charge about $5.50 per key, so the small upfront fees vary by office.
Because pricing is set per location and per size, the only way to know your exact cost is to check the specific post office you plan to use. USPS lets you search availability and prices by ZIP code on usps.com, where you can compare nearby offices and reserve a box online.
Frequently asked questions
- What is the cheapest PO Box?
- A small (Size 1) box at a rural post office on a 12-month term is the least expensive, sometimes around $60 per year.
- Is a 3-month or 12-month PO Box cheaper?
- The 12-month term is cheaper per month, typically saving about 10% to 15% versus paying every 3 months.
- Why do PO Box prices differ between post offices?
- USPS prices by location group. Rural offices charge the least, while busy big-city offices charge premium rates for the same size box.
Researched and edited by Calvin Lauderdale, Lead Researcher & Editor. Figures on this page were verified against the sources above as of June 23, 2026.