If your local post office is out of stock or you need a specific size not offered by USPS, you can buy individual or bulk boxes at: Ordering Free Shipping Supplies - FAQ | USPS
: Many branches sell a line called "ReadyPost," which includes sturdy cardboard boxes, bubble mailers, and tape.
: You can pick up single quantities of Priority Mail and Priority Mail Express boxes at most local branches.
The USPS Store provides packaging at no cost for its premium services.
If you are using or need general-purpose packaging, you must either provide your own box or purchase one at the retail counter.
: These boxes must be used with the specific service printed on them (e.g., you cannot use a Priority Mail box for Ground Advantage). Common Types :
: Non-flat-rate boxes where the shipping price is based on weight and distance. 2. Paid Shipping Boxes (ReadyPost)
: These boxes can be used for any mail class, but they are not free like the Priority Mail versions. 3. Alternative Purchase Locations