Free tool · USPS flat rule

Does my postcard qualify for EDDM?

An EDDM piece must be a USPS "flat": longer than 10.5 inches, or taller than 6.125 inches, or thicker than 0.25 inches, and no larger than 15 × 12 inches and 0.75 inches thick. A 4 × 6, 5.5 × 8.5 or 6 × 9 postcard does not qualify. Enter your size below to check it.

Common sizes

Width (inches)

Height (inches)

Thickness (inches) A 14pt or 16pt postcard is about 0.014 to 0.016 inches thick. Change this only for folded or bulky pieces.

The USPS rule for EDDM sizes

EDDM mail must be a flat. A piece is a flat when at least one of these is true:

the long side is more than 10.5 inches,
the short side is more than 6.125 inches, or
the piece is more than 0.25 inches thick,

and it is no larger than 15 × 12 inches and 0.75 inches thick. EDDM Retail pieces can weigh up to 3.3 ounces.

EDDM postcard sizes we print

Size	Why it qualifies	2,500 from
4.25″ × 11″	Long side over 10.5″	$309
6.5″ × 9″	Short side over 6.125″	$359
6″ × 11″	Long side over 10.5″	$399
8.5″ × 11″	Long side over 10.5″	$549
9″ × 12″	Long side over 10.5″	$559

EDDM size checker: questions and answers

What size does a postcard have to be for EDDM?

At least one of these must be true: the long side is more than 10.5 inches, the short side is more than 6.125 inches, or the piece is more than 0.25 inches thick. It also cannot be larger than 15 × 12 inches or thicker than 0.75 inches. Popular EDDM sizes are 6.25 × 9, 6 × 11, 8.5 × 11 and 9 × 12 inches.

Is a 6 × 9 postcard EDDM-eligible?

No. A 6 × 9 inch postcard is not longer than 10.5 inches and not taller than 6.125 inches, so it is not a flat. A 6.25 × 9 or 6.5 × 9 inch card does qualify because its short side is over 6.125 inches.

Is a 4 × 6 postcard EDDM-eligible?

No. A 4 × 6 postcard is a letter-size card. It can be mailed First-Class or as marketing mail with addresses, but not through EDDM.

Is there a weight limit for EDDM?

Yes. EDDM Retail pieces can weigh up to 3.3 ounces. A single postcard on 14pt or 16pt card stock is far below that.

Why does USPS require a flat for EDDM?

EDDM mail is delivered without an address, in bundles that carriers sort by route. The flat size keeps the pieces separate from addressed letter mail and handled the same way as other saturation flats.

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Talk to a print specialist, not a form.

Tell us what you're mailing and to whom. We'll price it, suggest the right size and help you pick EDDM routes, free. 7am–7pm ET, 7 days a week.

512-573-1977

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