How to Mail Postcards: USPS Sizes, Stamps and Batches

What size qualifies for USPS retail postcard postage?

Retail First-Class Mail postcards must measure at least 3.5 in high by 5 in long and no more than 4.25 in high by 6 in long. Thickness must be 0.007 to 0.016 in. These are the retail card dimensions in USPS DMM 101, section 6.2.

Our 4x6 in postcards use 16pt stock, nominally 0.016 in thick, so they sit within those size and thickness limits. Keep the finished piece flat and rectangular. Additional material or unusual preparation can change eligibility; have USPS check the actual piece if you modify it.

For an ordinary retail mailing with stamps, 5x7 and 6x9 in cards exceed the postcard-rate dimensions and mail as letters when they meet letter standards. USPS explains the distinction on its First-Class Mail page. Do not buy postcard stamps for those larger cards without confirming the correct postage.

Confirm the mail class and price for your piece with USPS before you buy postage.

The postcard size guide compares the printed formats when you need more room for the message.

How should you lay out the address side?

Keep the delivery address and postage together on the address side, with clear space for postal markings. USPS Postal Explorer's mailpiece layout guidance explains the address and marking areas; use it to review the design before printing.

For a conventional landscape card, reserve the right portion for the delivery address and postage and use the left portion for the message. Keep the address parallel to the long edge. Use a light, uncluttered address background and put the return address where it remains distinct from the recipient's address.

This is general layout guidance, not a measured postal template. The clear areas needed depend on the mailing method and preparation. A print margin is not a substitute for a postal address area, barcode area or postage position. Ask USPS to review the layout if you plan a permit or commercial mailing.

Treat the front as the message face: one image or offer, a readable headline and a clear next action. On the back, avoid filling every available space with marketing copy before allowing for mailing information.

Should you use stamps, a permit or EDDM?

Use stamps for individually addressed retail mail, investigate a permit for a prepared business mailing, and use EDDM only when route coverage fits your objective. These are USPS mailing choices, not services supplied with our printing.

Stamps: You address each card, apply the correct postage and submit it through USPS. The USPS guide to sending letters and postcards covers this process. Check the current rate there rather than relying on a postage amount printed in an old campaign plan.

Permit imprint: USPS describes a postage account and an approved postage block, often called an indicia, in its permit imprint guidance. Confirm eligibility, payment and acceptance requirements with USPS before preparing a permit mailing. A printed "postage paid" graphic does not establish an account or pay for delivery. We do not set up permits or indicia.

Every Door Direct Mail: USPS EDDM lets you select delivery routes rather than supply a list of named recipients. It has its own mailpiece requirements, route counts, markings, forms and bundles. EDDM Retail does not require a special mailing permit, but it still requires correct preparation and paid postage. Check the USPS size checker before ordering; do not assume a standard postcard qualifies for EDDM.

We do not mail, address or print variable recipient data on cards. We also do not sell postage or mailing lists, prepare EDDM bundles or set up EDDM. You arrange those tasks with USPS yourself or through a separate service.

How do you mail a batch yourself?

Prepare a stamped batch by settling the recipient count, ordering the cards, applying addresses and postage, and taking the completed mailing to USPS. Use the following sequence as a working checklist.

1. Count the usable addresses. Remove duplicates and confirm street, unit and ZIP Code details. Keep the working list separate from the shared artwork, since we do not print variable addresses.
2. Choose the mailing method. For retail mail, confirm postcard or letter postage for the chosen size. Resolve permit or EDDM eligibility with USPS before ordering if using those methods.
3. Order the print quantity. Choose 100, 250 or 500 cards and leave enough for your planned handouts or record copy. Avoid buying a large reserve of a dated offer.
4. Review both faces. Check the offer, dates, contact details and mailing space on the digital proof. Test any QR code and confirm that the destination page is ready.
5. Apply the addresses. Use clearly printed labels or another legible method suited to the surface. Test label adhesion on the gloss finish before processing the whole stack.
6. Check postage on a finished sample. Include the labels and any other additions. Confirm current postage with USPS, then apply it consistently to the remaining cards.
7. Submit and record the batch. Take the completed cards to USPS using the acceptance instructions for your chosen method. Save a copy of the design and note the mailing date and count.

How much do printed postcards cost before mailing?

250 double-sided 4x6 in Standard 16pt Gloss postcards cost $106.99 before artwork preparation, shipping and postage. All three sizes print full color on both sides at no extra side charge.

Choose the configuration on the custom postcards product page. The page lists a maximum of 500 cards per run; request a quote for larger quantities. The postcard paper stock guide explains the gloss surface if handwriting is part of your plan.

How do you prepare artwork and plan the schedule?

Postcard production takes 48 hours after artwork approval, followed by about 3 business days of ground transit. Approve on a weekday before 12 PM Central for production to start the next business day; after-noon or weekend approval counts from the next business day.

Extend backgrounds 0.125 in beyond each trim edge and keep text at least 0.25 in inside the trim. Those print margins apply to both faces and are separate from the postal layout. Ground shipping is flat $10 per product nationwide.

There is no production setup fee. Preparing your existing file or AI-generated image costs $14.99 per item. "Design it for me" is +$29.99 with two revisions and is free when the item itself is $499 or more. The free digital proof arrives after the order, before production.

For a permitted door-delivery alternative, compare door hangers versus postcards before committing to a mailing budget.

Need custom postcards or other custom printing? Inline Graphics helps businesses, churches, schools, and event organizers across the country design and print cards, banners, signs, decals, displays, and marketing materials that get noticed. Contact us today for a quote.