Priority Mail Express offers guaranteed overnight service for most zip codes. If you need guaranteed delivery by a certain day, ship with Priority Mail Express. The Post Office™ or our built-in NeoShip software can tell you the estimated arrival date when you enter your location and destination, or you can refer to the USPS zone map. If your package is time-sensitive, check whether Priority Mail takes 1, 2, or 3 days to reach its destination. However, it takes three days to ship from the same destination to Cheyenne, Wyoming. For example, it takes two days to ship a package from New York City, New York, to San Francisco, California. Priority Mail takes 1, 2, or 3 days depending on your location and the shipping destination.

For more on flat rate boxes and how much they cost, check out our blog on flat rate boxes blog post. This is a valuable cost-savings option when you are sending heavy items. Priority Mail flat rate boxes allow you to pay one flat rate regardless of how much your item weighs. These boxes can be ordered online or picked up at the Post Office™.

It delivers your packages in 1, 2, or 3 business days-including Saturdays! Send your items in regular packaging or use USPS® Priority Mail flat rate boxes. Priority Mail is one of the most popular services from the USPS®.

Usps priority mail flat rate shipping