Flat (USPS)

To fit the definition a flat 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. • Weigh no more than 13 ounces. Furthermore, the item must be somewhat bendable: see the USPS Domestic Mail Manual for exact details. This general rule does not apply to: Automation rate flats and Standard Mail Enhanced Carrier Route flats. ==Postage==

The maximum size for a flat provides enough room to enclose much material. An issue, however, is that the higher the weight the higher the postage, especially for First-Class Mail. == External links and references ==

• Domestic Mail Manual 101.2 Flats Physical Standards