Flats (USPS)

From Wikipedia, the free encyclopedia

This article may require cleanup to meet Wikipedia's quality standards.
Please improve this article if you can. (March 2007)

The Postal Service uses the words "flats" and "nonletters" to refer to large envelopes, newsletters, and magazines. The words are interchangeable. Whatever you call them, flats must:

Have one dimension that is greater than 6-1/8 inches high OR 11-½ inches long (the side parallel to the address as read) OR ¼ inch thick.
Be no more than 12 inches high x 15 inches long x ¾ inch thick.

NOTE: This general rule does not apply to:

Automation rate flats.
Standard Mail Enhanced Carrier Route flats.

The maximum size for a flat provides plenty of room to put lots of material in the envelope. But keep in mind that weight (usually affects rate) – the higher the weight the higher the postage, especially for First-Class Mail.

Is it possible to fold your flat-size piece to letter-size? If so, you can save money because you'll pay the lower letter rate.