Templates

All specification on the templates below should be strictly adhered to. Any noncompliance with this layout may result in a rejection by the postal authorities which may further result in your piece failing to qualify for the lowest possible postage rates.

Physical standards for machinable mail
Post card (First class only)
Letters (all classes)
Flats (all classes)
Postcard dimensions

Minimum Maximum
Length
5 inches
6 inches
Height
3 1/2 inches
4 1/4 inches
Thickness
0.007 inch
0.016 inch

Letter dimensions

Minimum Maximum
Length
5 inches
11 1/2 inches
Height
3 1/2 inches
6 1/8 inches
Thickness
0.007 inch
1/4 inch

Flats dimensions

Minimum Maximum
Length
11 1/2 inches
15 inches
Height
6 1/8 inches
12 inches
Thickness
1/4 inch 3/4 inch