USPS Flat Rate Box Shipping Cost

Wondering what a USPS flat rate box shipping cost is?

What's a Express Mail Flat Rate Box? Get these details and more with, the easiest and fastest way to send documents, letters, and forms online Here's what a Express Mail Flat Rate Box looks like:

USPS Flat Rate Shipping Box

To mail a package via USPS Express Mail, head over to your nearest post office. If you're sending a document, letter, form, manuscript, contract, or anything else that can be printed, check out