What Are the EDDM Postcard Size Requirements? (USPS Rules Explained)
EDDM requires mailpieces to be at least 6.125 x 10.5 — qualifying them as "flats." Here are all the USPS size rules and every compliant EDDM postcard size.
EDDM Size Requirements: Quick Answer
EDDM mailpieces must qualify as USPS "flats." The minimum size is 6.125 x 10.5 (one dimension must be at least 6.125", the other at least 10.5"). The maximum size is 12 x 15. Standard postcards (4 x 6, 5 x 7) do NOT qualify for EDDM — they're too small.
USPS EDDM Size Rules at a Glance
| Dimension | Minimum | Maximum |
|---|---|---|
| Height (shorter side) | 6.125" | 12" |
| Length (longer side) | 10.5" | 15" |
| Thickness | 0.009" | 0.75" |
| Weight | — | 3.3 oz per piece |
All EDDM-Compliant Postcard Sizes
| Size | Best For | EDDM Eligible |
|---|---|---|
| 6.25 x 9 | Most popular EDDM size — great balance of cost and impact | ✓ |
| 6.5 x 9 | Slightly larger, same affordability | ✓ |
| 8.5 x 11 | Letter-size impact, full content area | ✓ |
| 4.5 x 12 | Slim, unique format that stands out | ✓ |
| 6 x 12 | Wide panoramic format | ✓ |
| 6.5 x 12 | Larger panoramic option | ✓ |
| 9 x 11 | Near-letter size, premium feel | ✓ |
| 9 x 12 | Large format, high impact | ✓ |
| 8.5 x 14 | Legal size, great for menus | ✓ |
| 6.125 x 10.5 | True minimum EDDM size — lowest possible print cost | ✓ |
| 6.25 x 11 | Slightly taller than standard 6.25 x 9 — more vertical presence | ✓ |
| 6.5 x 11 | Mid-range panoramic — between 9" and 12" wide options | ✓ |
| 8 x 10.5 | Near-letter horizontal format, compact but substantial | ✓ |
| 11 x 14 | Near-tabloid — strong mailbox impact at lower cost than 11 x 17 | ✓ |
| 11 x 17 | Tabloid size — maximum mailbox presence | ✓ |
Why Do EDDM Pieces Need to Be Flats?
USPS categorizes mail by size: letters (small), flats (medium), and parcels (large). EDDM is a flat-rate product designed for flat-class mail. Requiring flat-size pieces ensures all EDDM mailings are processed on the same equipment and at the same rate — simplifying both delivery and pricing for mailers.
Design Bleed and Safe Zone Guidelines
- Bleed: Extend background images and colors 0.125" (⅛") beyond the finished trim size on all sides.
- Safe zone: Keep all text and critical design elements at least 0.125" inside the finished trim size.
- USPS indicia area: On the address side, leave the top-right 4 x 2.75 clear for the EDDM indicia or USPS postmark area.
- Resolution: All images should be at least 300 DPI at print size for sharp output.
Most Popular EDDM Size: 6.25 x 9
The 6.25 x 9 postcard is the go-to EDDM size for most businesses. It's the minimum EDDM-eligible size, which means lower per-piece printing cost while still providing a substantial canvas for your design. If your campaign is cost-sensitive, start here. Order EDDM in any size →
Choosing the Right EDDM Size for Your Business
The best EDDM postcard size depends on your content, budget, and campaign goal. Here's how to decide:
- Budget-first campaigns: 6.125 x 10.5 or 6.25 x 9 — the smallest qualifying sizes, lowest print cost per piece.
- Menu or multi-product campaigns: 8.5 x 11 or 8.5 x 14 — enough space for detailed product grids, pricing tables, or full menu layouts.
- Brand-impact campaigns: 9 x 12 or 11 x 17 — large format commands mailbox attention and conveys brand premium.
- Panoramic or slim layouts: 4.5 x 12 or 6 x 12 — distinctive proportions that stand out among standard-shaped mail.
- Vehicle or real estate photography: 11 x 14 or 11 x 17 — maximum canvas for full-bleed imagery.
Use our size and price calculator to compare per-piece printing costs across all eligible sizes before finalizing your campaign. You can also request a free quote customized to your postcard size and mailing volume. First-time mailers often find the 6.25 x 9 or 8.5 x 11 to be the best starting point before committing to a larger format.
Calculate pricing by postcard size → | Get a free quote →
Frequently Asked Questions
Can I use a standard 4 x 6 postcard for EDDM?
No. Standard postcards (4 x 6, 5 x 7) do not meet EDDM size requirements. EDDM requires flats with a minimum dimension of 6.125" on the shorter side.
What is the cheapest EDDM-compliant postcard size?
The 6.25 x 9 is typically the most affordable EDDM-eligible size — it's the smallest that qualifies, so printing costs are lowest while still delivering strong visual impact.
Is there a weight limit for EDDM pieces?
Yes — EDDM pieces cannot exceed 3.3 oz per piece. Standard postcard stock is well within this limit (typically 0.5–1.5 oz).
What's the maximum EDDM postcard size?
The maximum EDDM size is 12 x 15. The 11 x 17 tabloid is the most popular large-format option and fits within this limit.
Do folded mailers qualify for EDDM?
Yes — folded self-mailers can qualify for EDDM if the finished (folded) size meets the flat dimensions. The piece must still measure at least 6.125 x 10.5 when folded and must be tabbed or sealed per USPS requirements.
Does postcard size affect delivery time?
No. EDDM postage and delivery timelines are the same regardless of postcard size (within the flat size limits). A 6.25 x 9 delivers on the same schedule as an 11 x 17 — only the printing cost differs.