A Guide to Postcard Sizes for EDDM Success

Before you even think about launching a direct mail campaign, you need to get familiar with the rules of the road, and that means understanding the United States Postal Service (USPS) guidelines. Getting this right is the first step to success. For the EDDM program, there are very specific size requirements—your postcard must be at least 6.125 inches tall or 10.5 inches long, but can’t be bigger than 12 by 15 inches.

This isn't just red tape; following these rules is what qualifies your mailer for the program's awesome, cost-effective postage rates.

Navigating USPS EDDM Postcard Requirements

Think of the USPS guidelines as the blueprint for your direct mail campaign. These numbers aren’t arbitrary—they exist to make sure every single postcard can zip through the automated sorting machines smoothly and efficiently. Sticking to these rules is your guarantee that your message gets delivered without a hitch.

The USPS also says all EDDM mailers have to be rectangular with square corners. So, creative shapes like circles or triangles are out.

Beyond the basic length and height, thickness is another critical factor. Your postcard needs to be at least 0.007 inches thick, which is about the same sturdiness as three sheets of regular paper stacked together. The maximum thickness is 0.75 inches. This simple rule prevents flimsy mailers from getting mangled in transit, ensuring your piece arrives looking professional.

USPS EDDM Postcard Requirements at a Glance

To make it even easier, I've put together a quick reference table. These are the absolute must-knows to keep your campaign compliant.

Attribute	Minimum Requirement	Maximum Requirement
Height	3.5 inches	12 inches
Length	5 inches	15 inches
Thickness	0.007 inches	0.75 inches
Shape	Must be rectangular	Must be rectangular

Just keep this little cheat sheet handy, and you'll be in great shape.

The most important takeaway? At least one of your postcard's dimensions has to be larger than a standard postcard. This means your mailer must be taller than 6.125 inches OR longer than 10.5 inches to qualify.

As you're planning, don't forget about the printing method. Your choice between digital vs. offset printing will come down to factors like how many pieces you're sending, your budget, and the quality you're after. Thinking through these production details early on will save you headaches and help you manage your budget.

If you're ready to get started, you can explore a whole variety of https://www.4over4.com/printing/category/eddm that are already designed to meet these specs.

Picking the Most Popular Postcard Sizes

While the USPS gives you a lot of wiggle room on dimensions, most businesses that run successful EDDM campaigns tend to stick with a handful of proven sizes. There's a good reason these have become industry standards—they hit the sweet spot between mailing costs, mailbox impact, and having enough room for a message that actually sells.

Over the years, marketers have zeroed in on four main postcard sizes that just plain work. You'll see the Standard (6.25" x 9"), Large (6.25" x 11"), Jumbo (8.5" x 11"), and the impossible-to-miss Oversized (12" x 15") used time and time again. Campaign after campaign has shown these formats deliver the best bang for your buck, giving you enough design freedom to get noticed without breaking the bank.

The Four Industry-Standard Sizes

Think of each size as a different tool for a specific job. One might be perfect for a quick announcement, while another is better for telling a more detailed story. Figuring out their strengths is the first step to matching your postcard to your campaign goals.

• Standard (6.25" x 9"): This is the go-to for many businesses. It’s easy on the budget and gives you just enough space for a clear message and a strong call-to-action. Perfect for things like event reminders or simple sale announcements.
• Large (6.25" x 11"): Need a little more room to breathe? This size gives you extra horizontal space, which is great for bigger images and more text without a huge jump in cost.
• Jumbo (8.5" x 11"): Now we're talking. This postcard is the size of a standard piece of paper, so it’s guaranteed to stand out. It’s fantastic for things that need more detail, like restaurant menus, real estate listings, or a full list of services.
• Oversized (12" x 15"): If your goal is to completely dominate the mailbox, this is your weapon of choice. It's the largest option and makes a massive statement. Use this for high-impact campaigns where being seen is everything.

The real secret is choosing a size that not only fits your budget but also gives your message the right amount of space. A cluttered jumbo postcard is just as bad as a standard one where everything is cramped.

Getting the format right is a huge part of your campaign's success. It helps to check out different custom postcards printing options to really visualize how your design will look and feel on each size.

Choosing the Right Postcard Size for Your Goals

Picking the right postcard size for an EDDM campaign is way more than just a design choice. It's a strategic move that directly hits your campaign's budget, visibility, and whether it succeeds or fails. Think of it like choosing the right tool for a job. You wouldn't use a sledgehammer for a tiny nail, right? Same idea here—your postcard size has to match what you’re trying to achieve.

A smaller, more budget-friendly postcard like a 6.25" x 9" is fantastic for quick announcements, event reminders, or a straightforward coupon offer. Its biggest plus is the lower printing cost, which is perfect for businesses dipping their toes into direct mail or anyone on a tight marketing budget. The trade-off? Its smaller size can sometimes get lost in a cluttered mailbox.

Matching Size to Your Message

On the flip side, a big, bold format like the 8.5" x 11" jumbo postcard is built to make a statement. This size gives you all the room you need for eye-catching photos, detailed product galleries, or even a full service menu. It's the go-to for real estate agents showing off listings, restaurants with drool-worthy food pics, and any business that needs strong visuals to grab attention. Sure, the printing costs are higher, but the impact can easily justify the spend.

This graphic gives a quick breakdown of what you can expect to pay per piece for the most common postcard sizes.

As you can see, jumping to a larger size is just a modest bump in printing cost, but it can make a huge difference in how much you stand out.

The real secret is balancing your budget with your goal. A cheap postcard that nobody notices is just wasted money, but a huge, expensive mailer for a simple message is probably overkill.

Comparing Popular EDDM Postcard Sizes

To really nail this decision, it helps to see the options side-by-side. This table breaks down the pros, cons, and best uses for the four most popular EDDM-compliant sizes, making it easier to see the trade-offs between cost, space, and impact.

Size (Inches)	Best For	Pros	Cons
6.25" x 9"	Quick announcements, event reminders, simple coupons	Most affordable to print, great for high-volume sends	Easiest to overlook in a full mailbox
6.5" x 9"	Service promotions, small product features	Slightly more space than the smallest option, still very cost-effective	Still on the smaller side, limited design real estate
6.25" x 11"	Showcasing a few key products, detailed event info	Great balance of space and cost, stands out well	Higher printing cost than standard sizes
8.5" x 11"	Real estate listings, restaurant menus, brand showcases	Maximum impact and visibility, feels premium	Highest printing and postage cost of the bunch

When you weigh these factors against your specific campaign goals, the right choice usually becomes pretty clear.

Ultimately, the best postcard size is the one that fits your campaign. By thinking carefully about your goals, message, and budget, you can pick a format that gets your message into the right hands and makes a real impression. And if you want to make the whole process a breeze, exploring full-service direct mail services can give you expert guidance on everything from printing to mailing.

Designing for Impact on Any Postcard Size

A great design is what turns a piece of mail from junk into a powerful marketing tool. The postcard size you pick for your EDDM campaign will heavily shape your creative approach, influencing everything from font choices to how you place your images. Each dimension comes with its own set of opportunities and challenges for grabbing someone's attention.

With smaller, standard-sized postcards, the name of the game is ruthless simplicity. You only have a few seconds to make your case, so the design has to be direct and punchy. Your best bet is to focus on a single, bold headline that immediately gets your offer across, paired with a crystal-clear call-to-action (CTA) telling the reader exactly what to do next.

Mastering Your Creative Space

Jumping up to a larger format, like a jumbo 8.5" x 11" postcard, gives you a ton more creative real estate to play with. This extra room is perfect for high-impact visuals—think professional photos of a home for a real estate listing or mouth-watering pictures of dishes for a restaurant menu. You can also fit in detailed maps, multiple coupons, or more descriptive text without making the design feel cramped.

But no matter what postcard size you choose, some design principles never change. Visual hierarchy is absolutely critical; you have to guide the reader’s eye to the most important parts first using color, size, and smart placement.

Your main goal is to make the postcard scannable and instantly understandable. The average person decides whether to keep or toss a piece of mail in under three seconds. A clean design with plenty of white space is your best friend here, ensuring your message lands quickly.

For anyone looking to step up their game, leveraging accessible graphic design tools for effective visuals is a great starting point for creating compelling postcards. And if you really want to stand out from the stack of mail, you can even explore unique finishes. For instance, learning about the possibilities of custom die-cutting can give your postcard an unforgettable shape and feel.

Avoiding Common and Costly EDDM Mistakes

You’ve got a great design and picked the perfect postcard size for your EDDM campaign. That’s a fantastic start, but it's the small, simple mistakes that can completely derail your efforts and burn through your budget. Knowing the common pitfalls ahead of time is the best way to guarantee a smooth, successful mailing.

One of the most frequent slip-ups we see is misplacing the mailing indicia. That little box is what tells the USPS you've prepaid for postage. If it’s in the wrong spot or doesn't follow the specific formatting rules, your entire batch of postcards could get rejected on the spot. That means expensive reprints and major delays.

Another critical mistake is choosing the wrong paper stock. You might save a few bucks upfront on thinner paper, but flimsy postcards often show up in mailboxes looking like they've been through a warzone—bent, torn, and totally unprofessional. That damages your brand's credibility before anyone even reads your message.

Don't Let a Great Design Go to Waste

Beyond the technical stuff, design and messaging errors can be just as costly. A weak headline that fails to grab attention or a cluttered layout will get your mailer tossed in the recycling bin in seconds.

Similarly, a vague call-to-action (CTA) is a huge missed opportunity. If people don’t know what you want them to do next—whether it's "Visit Our Website," "Scan for 20% Off," or "Call Today"—they simply won't do anything. Your CTA has to be clear, compelling, and incredibly easy to follow.

To sidestep these issues, keep these points front and center:

• Proofread Everything: Seriously, check for typos everywhere—your headline, your offer, your contact info. A single wrong digit in a phone number makes the entire mailer useless.
• Use Strong Visuals: High-quality images that support your message are non-negotiable. Pixelated or generic stock photos will make your brand look amateurish.
• Have a Clear Offer: Make sure your promotion is dead simple to understand. Complicated terms or confusing discounts will only frustrate potential customers.

The most successful EDDM campaigns are the ones that nail both the technical details and the marketing message. Double-checking every single element, from the indicia placement to your headline's font size, is the secret to avoiding costly errors and getting the best possible return.

For a broader look at printed materials that can complement your direct mail, you can explore various options for custom flyer printing to maintain a consistent marketing message.

Got EDDM Questions? We’ve Got Answers.

Even the most buttoned-up EDDM plan can leave you with a few lingering questions. It happens to everyone. Let’s tackle some of the most common ones that pop up, so you can iron out those last few details and get your campaign out the door with confidence.

Can I Mail a Square Postcard with EDDM?

Nope, you can't. The USPS is pretty strict on this one—all EDDM mailers have to be rectangular.

If you send something square, circular, or in any other custom shape, it won't qualify for those sweet EDDM postage rates. More than likely, the post office will just reject it outright. Your best bet is to stick to the approved rectangular sizes to stay compliant.

Does a Larger Postcard Cost More to Mail?

This is where the magic of EDDM really shines. Surprisingly, the answer is no.

As long as your postcard fits within the approved postcard sizes for eddm and weighs less than 3.3 ounces, the postage cost is exactly the same. That means a massive 8.5" x 11" jumbo postcard costs the same to mail as a smaller 6.25" x 9" piece. The only difference you'll see is in your printing bill.

The flat-rate postage for all compliant EDDM sizes is a huge perk. It gives you the freedom to pick a postcard size based on your marketing goals and design—not your postage budget. You can go big and bold without getting penalized by the USPS.

What Is the Best Postcard Size for Real Estate?

From what we've seen, most real estate agents get the biggest bang for their buck with larger formats. Think the 8.5" x 11" Jumbo or the 6.25" x 11" Large postcard.

These bigger sizes give you plenty of room to show off stunning property photos, write detailed descriptions, include floor plans, and make your agent branding impossible to miss. A larger postcard doesn't just grab attention in a full mailbox; it also projects a professional, high-end image for your listings.

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Ready to create a postcard that actually gets noticed? 4OVER4 offers a huge selection of EDDM-compliant postcard sizes and top-notch printing to make your next direct mail campaign a winner. Design your perfect postcard today.