USPS RULES · 7 MIN READ

USPS EDDM size requirements: 6.5x9, 6x11, and 8.5x11 rules made simple

USPS Every Door Direct Mail offers the lowest postage rates available, but postal clerks will reject an entire print run if dimensions or indicia placement fail Domestic Mail Manual (DMM) standards by a fraction of an inch. Here are the exact rules to pass inspection every time.

What Qualifies as an EDDM 'Flat'?

To qualify for EDDM saturation rates, a mailpiece must be classified by USPS as a Flat. It cannot be classified as a letter, and it cannot be classified as a parcel.

According to USPS Domestic Mail Manual Section 101, to qualify as an EDDM flat, the piece must meet AT LEAST ONE of the following minimum dimensions:

• More than 10.5 inches in length, OR
• More than 6.125 inches in height, OR
• More than 0.25 inches thick (standard postcards never reach this thickness, so length or height must qualify).

Additionally, it must not exceed the maximum parameters: 15 inches long, 12 inches high, or 0.75 inches thick.

The Most Popular USPS-Approved EDDM Dimensions

Here are the four standard formats engineered to meet USPS Flat regulations with zero waste on press sheets:

• 6.5" x 9" (The Compact Champion): Qualifies because 6.5" exceeds the 6.125" height minimum. Extremely cost-effective, easy to bundle, and fits comfortably in letter-carrier satchels.
• 6" x 11" (The Mailbox Dominator): Qualifies because 11" exceeds the 10.5" length minimum. This is the single most popular EDDM size in America. Its long horizontal profile sticks out past standard letter envelopes in mailbox bundles.
• 8.5" x 11" (The Full Letter Page): Qualifies on both length and height. Huge surface area for grocery circulars, home service seasonal guides, and restaurant menus.
• 9" x 12" (The Jumbo Giant): The largest standard flat format. Dominates the kitchen countertop and commands total visual attention.

Mandatory Postal Indicia and Address Block Specs

Every EDDM mailer must carry the official USPS EDDM Retail Indicia and address block in the upper right quadrant of the address side:

• The EDDM Retail Indicia: A bordered rectangular box containing:
  PRSRT STD
ECRWSS
U.S. POSTAGE PAID
EDDM RETAIL
• The Simplified Address Block: Must be placed directly below or beside the indicia:
  Postal Customer
City, State, ZIP
  (Or "Local Postal Customer" to deliver to both residential and business addresses).
• Clear Space Zone: Keep a clear buffer zone of at least 1/8" around the address block and indicia free of dark graphics or dense typography.

Paper Weight and Caliper Requirements

USPS requires all flats to be at least 0.007 inches (7 points) thick. When printing oversized pieces like 6x11 or 8.5x11, thin stocks flop over and jam automated sorting equipment.

Commercial printers produce EDDM postcards exclusively on 14pt or 16pt cardstock. This guarantees smooth processing, prevents dog-eared corners, and delivers a commanding, professional tactile feel to homeowners.