Effective January 9, 2022. Learn more about 2022 rates.
First-Class Mail is one of USPS's premium services. It is often as fast as Priority Mail, with delivery estimated between 1-3 days. Learn more about USPS First-Class Mail.
Large Envelope / Flats
Large Envelope Flats is a special service within First-Class Mail. Flats are large envelopes smaller than 11.5" x 15" but larger than a regular envelope. Regular Envelopes are the standard of business envelopes. This product range includes the popular No.10 envelope, which measures 9-1/2" long x 4-1/8" high.
Compare with First-Class Mail® Forever® Stamp
USPS offers Forever Stamps that value at the same price as a regular First-Class Mail stamp, regardless of the rate when you purchased it.
You can send 1 oz (about four sheets of regular, 8-1/2" x 11" paper in an envelope) anywhere in the U.S. Envelopes must be rectangular and made of paper to qualify for letter prices. Your envelope can be a maximum of 11-1/2" long x 6-1/8" high. You can fold what you put in your envelope, but it needs to stay flat—no more than 1/4" thick.
You can use two Forever Stamps if you need to send a package or a letter that weighs more than an ounce.
Anything weighing over 3 oz would cost $1.80 at the current value of a Forever Stamp and only $1.68 using First-Class Mail Large Envelopes / Flats.
First-Class Mail rates are based on parcel weights and rate class.
Retail pricing is offered directly from the USPS at Post Office retail locations or USPS.com. It does not include discounts on postage prices like those received via ShippingEasy.
Compare with First-Class Mail Flats | Retail
USPS provides a multitude of services and rate classes. Check out these similar services and rates to see how they compare: