EDDM Postcard Size Guide: Mailing Requirements and Best Sizes

Postcards remain a favorite among businesses when it comes to Every Door Direct Mail (EDDM) marketing. They’re affordable, eye-catching, and informative, perfect for an area-wide promotional campaign that showcases your brand’s products, services, and special offers to all households’ mailboxes.

But before you start printing and sending postcards, it’s essential to follow EDDM guidelines implemented by the USPS, especially when it comes to postcard size.

In this article, we outline the official size rules and share which postcard dimensions work best to create a powerful first impression.

USPS Size Requirements for EDDM Postcards

Postcard sizes and dimensions are often vital when designing its layout and artwork. When it comes to EDDM, the USPS has set standards in place to ensure every postcard qualifies for the service and can be handled easily and consistently during mailing across a region.

USPS requires that all EDDM postcards follow these key rules:

The postcard must be rectangular for easier sorting and automation.
Its length should be between 3.5″ and 15″.
Its height should measure between 3.5″ and 12″.
Its thickness must fall between 0.007″ and 0.75″.

While these size rules remain consistent with both Business Mail Entry Unit (BMEU) and Retail postcards, there are some additional guidelines in place for the latter. Simply put, retail EDDM postcards must meet one of the following minimum size requirements, while also adhering to all these maximum requirements.

	Minimum	Maximum
Height	It must be taller than 6.125″.	It should be no taller than 12″.
Width	It must be longer than 11.5″.	Width should not exceed 15″.
Thickness	Postcard should be thicker than 0.25″.	It can’t be thicker than 0.75.

What are the Best EDDM Postcard Sizes?

The USPS provides a range of dimensions so your EDDM postcards will be fine so long as they land in that size range. Still, there are specific sizes that are widely used for uniformity and grabbing attention, all while keeping costs in check. Here are some of the commonly used sizes for your postcards.

6.5″ x 9″

This size is often the standard for postcards, giving you plenty of room for strong visuals, concise messaging, and clear calls-to-action.
It is commonly used for standard promotions, grand openings, exclusive sales, and product launches that require a bold yet affordable direct-mail approach.
This size often boasts a clean design with a large hero image at the top, paired with a simple, eye-catching headline and a clear call-to-action at the bottom.

6.5″ x 8″

This slightly compact postcard size is ideal if you want a standout piece that is easy to distribute.
Businesses often choose this format for seasonal promotions, event invitations, or local service announcements that need quick visibility without overwhelming details.
A bright, colorful background with minimal text and accompanying images ensures your message is visible on this slightly smaller postcard.

8.5″ x 11″

The letter-size postcard offers generous space, perfect for showcasing multiple products, detailed service descriptions, or promotional offers that remain easy to read and visually appealing.
Retailers and real estate agents often mail this size to present product catalogs, property listings, or multi-offer sales events where extra room is essential.
A grid-style layout featuring multiple product images, or a full-page lifestyle photo with smaller textboxes, makes excellent use of the extra space.

6.5″ x 12″

The extra-wide layout will immediately stand out, making it an excellent choice for campaigns that need bold headlines and striking imagery to stand out in crowded mailboxes.
It’s commonly used for high-level promotions such as major store openings, luxury product launches, or event marketing. The focus of these postcards should create excitement.
A panoramic image or full-bleed background photo with large, contrasting text and a strong call-to-action captures attention and maximizes the postcard’s wide format.

The USPS size requirements aren’t restrictive and actually help with the timely delivery of your EDDM postcards. Sticking to these size rules ensures smooth processing and on-time delivery, saving you from unexpected delays or extra fees, all while keeping your promotional schedule intact.

PrintPlace offers professional EDDM postcard printing, including the option to choose the appropriate postcard size that fits both the USPS standard and your promotional campaign. You can then focus on creating a design that matches your selected size and forward your postcards to connect with people at their doorstep.