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 that are 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 #10 envelope which measures 4 1/8" by 9 1/2".
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.
[Learn more about USPS Retail pricing].
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:
Effective January 24, 2021. Learn more about 2021 rates.