Are all priority mail boxes flat rate

No, not all Priority Mail boxes are flat rate. While the United States Postal Service (USPS) does offer flat rate boxes for Priority Mail, there are also other types of Priority Mail boxes that are not flat rate.

Here are the different types of Priority Mail boxes:

  1. Flat Rate Boxes: These boxes have a fixed price regardless of the weight or size of the package. There are several sizes to choose from, including Small, Medium, Large, and Regional Rate Boxes. The prices for flat rate boxes are:
    • Small: $7.50
    • Medium: $13.75
    • Large: $19.95
    • Regional Rate Box A: $14.35 (for packages up to 70 lbs)
    • Regional Rate Box B: $19.95 (for packages up to 70 lbs)
  2. Variable Rate Boxes: These boxes have a price that is based on the weight and size of the package. You can use a Priority Mail scale to determine the cost.
  3. Priority Mail Envelopes: These are envelopes that are designed for sending documents and packages that don't require a box. The prices for Priority Mail envelopes vary based on the weight and size of the package.
  4. Priority Mail Padded Envelopes: These are envelopes with extra padding to protect fragile items. The prices for Priority Mail padded envelopes vary based on the weight and size of the package.

It's worth noting that while not all Priority Mail boxes are flat rate, you can still use a flat rate box for a package that weighs more than the maximum weight for the box. In this case, you'll need to pay the difference in weight-based postage.