143.2.5: the EDDM test
An EDDM Retail flat must weigh no more than 3.3 ounces and have:
- a length greater than 10-1/2 inches, or
- a height greater than 6-1/8 inches, or
- a thickness greater than 1/4 inch.
Only one of the three has to be true. This is an exception for EDDM Retail. Regular flats must be bigger than letter size, which means longer than 11-1/2 inches, taller than 6-1/8 inches or thicker than 1/4 inch.
101.2: the general flat rules
- Maximum: 15 inches long, 12 inches high, 3/4 inch thick.
- Length is the longest dimension.
- Rectangular, with square corners or corners rounded no more than 1/8 inch.
- Uniformly thick: bumps can't make the thickness vary by more than 1/4 inch.
- Flexible. A rigid piece isn't a flat.
Reading the rules together
| Piece | 143 test | 101 limits | Result |
|---|---|---|---|
| 6 x 9 card | Fails (no side big enough) | Passes | Not EDDM Retail |
| 6.25 x 9 card | Passes (height over 6-1/8) | Passes | Qualifies |
| 6 x 11 card | Passes (length over 10-1/2) | Passes | Qualifies |
| 12 x 15 card | Passes | Passes (at the maximum) | Qualifies |
| 9 x 12 rigid board | Passes | Fails (not flexible) | Not a flat |
Questions
What sizes qualify for Every Door Direct Mail?
Any flat over 10.5 inches long, over 6.125 inches high or over 0.25 inch thick, up to 15 x 12 x 0.75 inches and 3.3 ounces.
How does USPS measure the length of a flat?
Length is the longest dimension.
Can EDDM pieces have rounded corners?
Yes, if the corner radius is no more than 1/8 inch.