In essence, there is only one main difference between flat rate and Priority Mail: the price. All of your shipments are shipped in Flat Rate Boxes. Shipping with Flat Rate Boxes is a breeze. As long ...

USPS is increasing rates in parcel delivery services, effective this week. Here's what to know about the cost to ship your packages.

The price of a Priority Mail flat rate envelope (size 12-1/2″ x 9-1/2″) will jump from $10.45 to $10.78 while the Priority Mail Express flat rate envelope (size 12-1/2″ x 9-1/2″) will jump ...