Quick answer
Priority Mail and Priority Mail Express boxes and envelopes from USPS are free: USPS says Priority Mail packaging is free when you pay for Priority Mail shipping service. Order them from the USPS Postal Store, which ships them at no cost to the customer, or pick up select boxes at a Post Office. Free Priority Mail supplies may only be used to ship via Priority Mail, so they cannot carry USPS Ground Advantage, which needs your own box.
Nation, an AI store builder, publishes this page. It is pre-launch, with a waitlist on withnation.ai, so it is not in any comparison. See where Nation fits.
Which USPS boxes are free
The free USPS boxes are the ones printed for Priority Mail and Priority Mail Express. USPS says Priority Mail envelopes and boxes are free when you pay for Priority Mail shipping service, and Priority Mail Express Flat Rate envelopes are free when you pay for USPS® Priority Mail Express Flat Rate shipping service. You can order Priority Mail and Priority Mail Express boxes at no extra charge, so the only thing you pay for is the postage.
Each free box is tied to its service. Priority Mail shipping supplies may only be used to ship via Priority Mail. USPS Ground Advantage has no free boxes for most shippers: its page tells you to use your own packaging and measure it to make sure it meets the size standards. The USPS boxes are optional for Priority Mail too, since USPS says you are not required to use the free packaging.
The free packaging falls into three groups:
- Priority Mail Flat Rate boxes and envelopes. Each one ships for a single price set by the box, for any weight up to 70 lbs.
- Priority Mail boxes without Flat Rate printing, such as the Priority Mail Small Box. They are free too, but postage is based on weight, dimensions, and destination, as it is for your own box.
- Priority Mail Express envelopes and boxes. They are free for Priority Mail Express only. The Express Flat Rate envelope, for example, may only be used to ship via Priority Mail Express Flat Rate.
USPS free boxes: sizes and prices
Flat Rate products let you ship packages up to 70 lbs to any state at the same price. The price is set by the box. USPS publishes two prices for each one: the Post Office price, and a Commercial price for labels bought online, where USPS says you get lower Commercial Rates. The prices below come from the USPS price list effective July 12, 2026, except the Board Game Box, which is listed on the USPS Priority Mail page.
The box has to close the way it was made: the container flaps must be able to close within the normal folds.
Flat Rate packaging is tied to the Flat Rate price. USPS says Flat Rate shipping supplies may only be used to ship via Priority Mail Flat Rate, so you cannot put a Flat Rate box on the scale and pay by weight instead.
Two of the envelopes are not on the counter. In the USPS price list, the Legal and Padded Flat Rate Envelopes are marked only available at USPS.com.
Can you use free USPS boxes for Ground Advantage?
No. The USPS Domestic Mail Manual says all USPS-produced packaging, Flat Rate included, must be used only for the applicable product (e.g., Priority Mail Express, Priority Mail). The Postal Store product pages say the same in plain words: Priority Mail shipping supplies may only be used to ship via Priority Mail.
Turning the box inside out or covering the logo does not get around this. The manual says the mailer of anything sent in USPS packaging, regardless of how the packaging is reconfigured or how markings may be obliterated, must pay the appropriate product price. So a parcel in Priority Mail packaging owes Priority Mail postage, even with a Ground Advantage label on it.
For Ground Advantage, USPS tells you to use your own packaging and measure it to make sure it meets the size standards. The exception is for businesses with a contract: USPS says they can ship with a Negotiated Service Agreement and use the exclusive USPS Ground Advantage boxes. A Negotiated Service Agreement is available for larger volume shippers who meet the minimum volume requirements, so most small shops use their own boxes.
Two more rules apply to the free Priority Mail boxes. USPS-produced packaging must not be used for shipping mailable hazardous material or live animals. The manual's exception is that USPS Ground Advantage and USPS Connect Local USPS-produced packaging may be used for shipping mailable hazardous material, so hazardous items do not go in a free Priority Mail box. And if you send a Priority Mail box abroad, it is charged at Priority Mail International prices.
For Ground Advantage, the free option is a box you already have. A plain box from a delivery you received works if it meets the size standards. USPS says that if you are reusing a box, totally remove or obliterate all previous labels and markings with heavy black marker. This does not work for a used Priority Mail box, which stays Priority Mail packaging however you mark it.
How to order free USPS shipping supplies
USPS mails its free supplies to your door. To order by phone or online, call 1·800·222·1811 or visit www.usps.com/store.
Pick the service before the box
Decide whether the parcel goes by Priority Mail or Ground Advantage. The free boxes are for Priority Mail and Priority Mail Express only, so a Ground Advantage parcel needs your own box.
Open the free shipping supplies section
On the USPS Postal Store, open Shipping Supplies and filter by Free Shipping Supplies. The item page says which service the packaging may be used for.
Choose the pack size
Pack sizes vary by item. The Medium Flat Rate Box ships in single, or a pack of 10 or 25 boxes, and the Flat Rate Envelope ships in single, or a pack of 10 envelopes. Order what you expect to ship in the next few weeks.
Check out with free delivery
The packaging costs nothing, and the Postal Store sends it by Ground Advantage at no cost to the customer.
Allow time for delivery
USPS says boxes and envelopes are delivered with your regular mail usually within 7 to 10 days. Order before you run out, and pick up a few at a Post Office if a parcel cannot wait.
Ship at the matching price
Buy the Priority Mail label online for the Commercial price, or pay at the counter. A Flat Rate box goes at its Flat Rate price, because Flat Rate supplies may only be used to ship via Priority Mail Flat Rate.
USPS free boxes in store
Post Offices give out free packaging too. USPS says select Priority Mail Express and Priority Mail boxes are available free at the Post Office for items sent using either of these services. The word select matters: the counter does not promise every size, and the Legal and Padded Flat Rate Envelopes are only available at USPS.com.
The same rule applies in store as online: the box is free because you will pay Priority Mail or Priority Mail Express postage on it. Other boxes at the counter are a different product. You can purchase boxes and tubes of various sizes at most Post Offices, but they are sold, not given away.
When a free Flat Rate box is the cheaper choice
A free box saves money only when the postage on it is lower than the other options. You pay for a Ground Advantage parcel based on how much it weighs and how far it’s going (the zone), and Priority Mail prices outside Flat Rate are based on weight and zone. A Flat Rate box costs the same at any weight and distance, so it is most likely to save money on heavy parcels going far.
Example: two parcels shipped with Commercial prices from the USPS price list. The first weighs 1 lb, goes to zone 5 and fits the Small Flat Rate Box. The second weighs 10 lb, goes to zone 8 and fits the Medium Flat Rate Box. Your own box for Ground Advantage is assumed small enough that dimensional weight does not apply.
For the light parcel, Ground Advantage in your own box costs less than any free box. For the heavy one, the free Medium Flat Rate Box costs less than Ground Advantage and travels at Priority Mail speed, 2-3 days instead of 2-5 days. Run your real weight, box size and ZIP codes through the USPS price calculator before you choose.
Where Nation fits
Nation
Category: an AI store builder
Nation says one description of what you make builds the store, then agents handle orders, customers and delivery and run ads, content and social posts, with you approving the work. Because pricing is not announced yet, it is not compared on this page.
Limits today
- Status: pre-launch, with a waitlist on withnation.ai.
- Pricing and fees: not announced yet.
- Shopper marketplace: no shopper marketplace has been announced.
- Track record: no independent reviews or public stores yet.
Nation publishes this page. The shipping rules and prices on it come from USPS's own pages.
Describe what you makeQuestions about free USPS boxes
Are USPS boxes really free?
USPS boxes are free when you use them for the service they are made for. Priority Mail boxes and envelopes are free when you pay for Priority Mail shipping service, and Priority Mail Express Flat Rate envelopes are free when you pay for USPS® Priority Mail Express Flat Rate shipping service. You still pay postage on every package, and the free boxes cannot carry USPS Ground Advantage.
Can I use a free Priority Mail box for Ground Advantage?
A free Priority Mail box cannot be used for USPS Ground Advantage. USPS says Priority Mail shipping supplies may only be used to ship via Priority Mail. Its mail manual adds that the mailer, regardless of how the packaging is reconfigured or how markings may be obliterated, must pay the appropriate product price, so turning the box inside out does not help. Ground Advantage needs a plain or reused box.
Are there free boxes for USPS Ground Advantage?
USPS does not offer free Ground Advantage boxes to most shippers. Its Ground Advantage page tells you to use your own packaging and measure it to make sure it meets the size standards. USPS says businesses can ship with a Negotiated Service Agreement and use the exclusive USPS Ground Advantage boxes, an agreement available for larger volume shippers who meet the minimum volume requirements. Others use a plain box.
How long do free USPS boxes take to arrive?
Free USPS boxes ordered online come by mail. USPS says boxes and envelopes are delivered with your regular mail usually within 7 to 10 days, and the Postal Store sends them at no cost to the customer. If you need a box sooner, USPS says select boxes are free at the Post Office, though not every size is on the counter.
Can I get free USPS boxes in store?
You can get free USPS boxes in store. USPS says select Priority Mail Express and Priority Mail boxes are available free at the Post Office for items sent using either of these services. Not every size is on the counter, and the Legal and Padded Flat Rate Envelopes are only available at USPS.com. Other boxes at the Post Office are for sale, not free.
What sizes do free USPS Flat Rate boxes come in?
The main free USPS Flat Rate boxes are small, medium and large. The Small Flat Rate Box is 8-5/8" x 5-3/8" x 1-5/8" inside, the Medium is 11" x 8-1/2" x 5-1/2" top-loading or 13-5/8" x 11-7/8" x 3-3/8" side-loading, and the Large is 12” x 11-3/4" x 5-1/2" inside. Each ships for one price up to 70 lbs.