While the boxes themselves are free from USPS, some third-party services sell "kits" or bundles that include extra supplies like tape or labels for convenience.
Check if a would be cheaper for your destination. Look up Post Office hours for a specific location. where can you buy usps flat rate boxes
If you need boxes in bulk, you can order them for free on the USPS Postal Store. While the boxes themselves are free from USPS,
Offers packs of boxes (though usually, these are still fulfilled through the USPS partnership). where can you buy usps flat rate boxes
Find the for your specific package weight.
You can find Small, Medium, Large, and Specialty sizes (like the APO/FPO box for military mail). 🛒 Third-Party Alternatives