Each type of packaging is priced differently, and you can ship up to 70 pounds in each of them. The main thing you need to know about Priority Mail Flat Rate is that it comes with several different types of packaging that you can use. The Different Kinds of Flat Rate Packaging

You CANNOT use generic boxes or your own custom-branded packaging.USPS offers free boxes and envelopes for Priority Mail Flat Rate that you need to use.

$50 of insurance included when you buy postage the Post Office.$100 of built-in USPS insurance included (with Commercial Pricing rates).Delivery occurs between 1-3 business days anywhere in the United States.USPS Priority Mail Flat Rate: The Breakdown Here’s everything you need to know about USPS Priority Mail Flat Rate. The rates of this service don’t fluctuate based on how much your parcel weighs or where it’s going, which makes Flat Rate a popular USPS service amongst shippers throughout the country. The idea behind this service is that if you can fit something into a Flat Rate envelope or box, the price you pay is fixed (or “flat”). Priority Mail Flat Rate is a popular service offered by USPS.

Priority mail flat rate cost