A single-piece First-Class Mail postcard stamp cost is $0.65. This specific rate applies to rectangular cards measuring up to 4.25 inches high by 6 inches long. If your card exceeds these dimensions or features a square shape, it no longer qualifies for the postcard tier and requires standard letter postage instead.
Understanding how the United States Postal Service categorizes different mail pieces helps prevent returned mail or unexpected surcharges. Whether you're sending holiday greetings or launching a small business marketing campaign, knowing the exact specifications ensures your mail moves smoothly.
Current USPS postcard stamp pricing
The baseline retail price for mailing a standard domestic postcard sits at $0.65. You can purchase dedicated postcard stamps at this exact denomination, or you can use a regular Forever stamp. Sticking a standard Forever stamp (which costs $0.82) onto a postcard works fine, but you're paying an extra 17 cents more than necessary.
International postcards require a different approach. Sending a postcard to any destination outside the United States costs $1.75 using a Global Forever stamp. Domestic rates do not apply once a card crosses US borders.
Exact size and dimension requirements
The postal service enforces strict physical dimensions for the postcard rate. Exceeding these limits by even a fraction of an inch bumps your item into the more expensive letter category.
A card must meet these exact physical boundaries to qualify for the $0.65 rate:
- Minimum height: 3.5 inches
- Maximum height: 4.25 inches
- Minimum length: 5.0 inches
- Maximum length: 6.0 inches
- Thickness: Between 0.007 inches and 0.016 inches
Cards thicker than 0.016 inches or crafted from rigid materials cannot bend easily around sorting equipment. Irregular shapes, square formats, or items enclosed in envelopes automatically trigger letter or flat pricing rules. For precise sizing charts and official policy documents, check the USPS Domestic Mail Manual.
Bulk and commercial postcard mailing options
Sending hundreds or thousands of cards changes the financial math completely. Retail stamps become inefficient for high-volume senders. Businesses and organizations rely on commercial classes to reduce postage expenses.
Every Door Direct Mail (EDDM) Retail allows local businesses to saturate specific carrier routes without needing a physical mailing list. EDDM postage rates run around $0.26 per piece, provided you prepare and bundle the mail according to local post office requirements.
For targeted mailing lists containing 200 or more pieces, USPS Marketing Mail offers commercial automation pricing. Mixed-tier commercial rates drop per-piece costs significantly compared to retail stamps. Organizations can review current commercial price structures directly through Postal Explorer.
Common mistakes that trigger extra postage
Many senders lose money or face delivery delays due to simple oversights. Avoiding these frequent errors keeps your mail processing smoothly.
- Using oversized cardstock: Cutting a card to 5 by 7 inches feels luxurious, but it disqualifies the item from the postcard rate. It must pay the full 1-ounce letter price.
- Mailing square formats: Square cards disrupt automated sorting machines. Even if a square card fits within standard length and height limits, USPS assesses non-machinable surcharges or letter rates.
- Forgetting thickness limits: Thicker craft papers or embellishments like glued-on items push the thickness past 0.016 inches, turning a simple postcard into a parcel or flat.
- Incorrect address orientation: The address block must run parallel to the longer edge of the card. Flipping the layout sideways confuses high-speed sorting cameras.
Frequently asked questions
Can I use old postcard stamps from past years?
Yes. Older postcard stamps remain valid for current postage. If postage rates increase, you can combine older denomination stamps with supplementary cent stamps to reach the current total required.
Do handmade photo postcards qualify for the postcard rate?
They qualify as long as they meet the rigid dimension and thickness rules. If you print a photo on heavy cardstock that exceeds 0.016 inches in thickness, it requires letter-rate postage.
What happens if I put a postcard stamp on an oversized card?
The post office may return the item to your return address for insufficient postage, or they may deliver it and collect the postage difference from the recipient upon delivery.
Are postcard stamps self-adhesive?
USPS issues both traditional water-activated gummed postcard stamps and modern self-adhesive peel-and-stick versions, depending on the specific design sheet purchased at the retail counter.
