Free mailing boxes from USPS®
USPS offers six free "mailing boxes" that you can use with Priority Mail Cubic or weight-based Priority Mail. Below, we've listed each of the boxes, their outer dimensions (OD), and which Priority Mail Cubic pricing tier they belong to:
Priority Mail Box - 1096L | OD: 9.25" x 6.25" x 2" | Cubic Tier 1
Priority Mail Box - 4 | OD: 7.25" x 7.25" x 6.5" | Cubic Tier 2
Priority Mail Box - 1097 | OD: 13" x 11.25" x 2.25" | Cubic Tier 2 *
Priority Mail Box - 1092 | OD: 13.68" x 12" x 2.875" | Cubic Tier 3
Priority Mail Box - 1095 | OD: 15" x 12" x 3.125" | Cubic Tier 4
Priority Mail Box - Shoe Box | OD: 7.25" x 5.25" x 14.75" | Cubic Tier 4
Order at USPS.com: You can order any of these boxes in bulk from USPS.com/supplies.
* Measured on the Priority Mail Box 1097 from July 2013. Box sizes may vary based on the date they were printed/produced. We here at Pirate Ship always recommend measuring these boxes yourself to ensure you are using the most correct dimensions.
How to use these boxes for your shipments on Pirate Ship
Here are some things to remember when you purchase labels for these boxes on Pirate Ship:
You MUST purchase Priority Mail postage to use these boxes (you cannot use them for USPS Ground Advantage or any other service).
Also, note that any USPS package that says "Flat Rate" on it requires that you buy the corresponding postage for that package type. You cannot use Flat Rate boxes for Priority Mail Cubic or weight-based Priority Mail, and vice versa.
USPS discontinued Priority Mail Regional Rate Boxes on January 22, 2023, but you can use those boxes for Priority Mail Cubic shipments if you have old ones lying around!
Need a box for Cubic Tier 5?
USPS doesn't provide any free mailing boxes compatible with Cubic Tier 5. However, if you're in search of a box around that size, you can order one from U-Haul here.
The outer dimensions of this box are 12" x 12" x 6" 👍