USPS Priority Mail Flat Rate

What is Priority Mail Flat Rate?

Priority Mail Flat Rate is a 1 to 3 day shipping service provided by the U.S. Postal Service (USPS) that features one flat rate for delivery of a package or envelope to its destination. The service allows a maximum weight of 70 lbs. or less for each envelope or package. Priority Mail Flat Rate includes free shipping supplies available at the Post Office or sent directly to your residence or business for no charge. Packaging options include three types of envelopes and six boxes in various sizes.

Flat rate pricing eliminates the need to weigh packages or calculate shipping fees, as long as the package weighs less than 70 lbs. Each Priority Mail Flat Rate Box and Envelope features one low flat rate, so pricing is determined by the box or envelope you choose and not by the weight or distance the package is traveling.

Try us out for 4 weeks! Get $5 in free postage

(to use during your trial).

Try us out for 4 weeks! Get $5 free postage

(to use during your trial)

Try us out for 4 weeks!

Get $5 free postage

(to use during your trial)

How to Send Packages with Priority Mail Flat Rate

Shipping a package or envelope using Priority Mail Flat Rate is very easy. Place your item in one of the many free Flat Rate boxes supplied by the USPS. As long as your item is not heavier than 70 lbs., you will not need to weigh the item.

Postage may be purchased either at the Post Office or online through an online postage provider. Once your package is ready to be shipped, you can schedule a free package pick-up from the USPS at your home or office.

Benefits Of Using Priority Mail Flat Rate With Stamps.com

Following are the Priority Mail Flat Rate options and specifications:

Priority Mail® Flat Rate Options Maximum Weight Outside Dimensions Post Office™ Rate Stamps.com Rate
Flat Rate Envelope up to 70 lbs. 12 1⁄2″ x 9 1⁄2″ $5.75 $5.05
Legal Flat Rate
Envelope
up to 70 lbs. 9 1⁄2″ x 15″ $5.90 $5.25
Padded Flat Rate
Envelope
up to 70 lbs. 12 1⁄2″ x 9 1⁄2″ $6.10 $5.70
Small Flat Rate Box up to 70 lbs. 8 11⁄16″ x 5 7⁄16″ x 1 3⁄4″ $5.95 $5.25
Medium Flat Rate Box
- Top Loading
up to 70 lbs. 11 1⁄4″ x 8 3⁄4″ x 6″ $12.65 $11.30
Medium Flat Rate Box
- Side Loading
up to 70 lbs. 14″ x 12″ x 3 1⁄2″ $12.65 $11.30
Large Flat Rate Box up to 70 lbs. 12 1⁄4″ x 12 1⁄4″ x 6″ $17.90 $15.80
APO/FPO Large Box up to 70 lbs. 12 1⁄4″ x 12 1⁄4″ x 6″ $15.90 $13.80
Swipe right to see entire table

Shipping with Priority Mail Flat Rate boxes or envelopes using Stamps.com can save you money. Stamps.com customers save up to 13% off the Post Office rate each time they print a shipping label for a Priority Mail Flat Rate envelope or box. Plus Stamps.com offers insurance coverage up to $10,000. And you can easily track your Priority Mail packages with “one-click” tracking, eliminating the need to type in long tracking numbers to verify delivery.


Try Stamps.com for 4 weeks!

Every new customer account starts with:

  • Free 5 lb. Digital Scale*, connects via USB
  • 4-week trial
  • $5 in free postage to use in trial period
  • Free Supplies Kit including postage labels
  • Additional $10 postage coupons to use after trial
    *pay only S&H fee