You’ll need to measure your package to make sure it meets the size standards.Pay for your package based on how much it weighs and how far it’s going (the zone).Use your own box and pay by weight and zone (distance): When sealing a Flat Rate Envelope or Box, the container flaps must be able to close within the normal folds.Use our Priority Mail Flat Rate Envelopes or Boxes that come in standard sizes so you don't have to worry about measuring them.Pay the same price for mailpieces weighing up to 70 lbs going anywhere in the U.S.Weight, Size, & Shape Requirements Use USPS Priority Mail Flat Rate packaging and pay one price:
