Postcard Stamps: 2026 Rates and Rules
Postcards are the cheapest mail format—but only if you follow the size rules.
Current Postcard Rate
As of July 12, 2026: $0.65.
Size Requirements
| Dimension | Minimum | Maximum |
|---|---|---|
| Height | 3.5 in | 4.25 in |
| Length | 5 in | 6 in |
| Thickness | 0.007 in | 0.016 in |
Exceeding any dimension = letter rate ($0.82+) applies.
Postcard vs. Forever Stamp
You can use a Forever stamp ($0.82) on a postcard—it overpays by $0.17. But you cannot use a postcard stamp ($0.65) on a letter.
Oversized Postcards
Many jumbo postcards at gift shops exceed the maximum dimensions. These require full letter-rate postage. Measure before stamping.
Frequently Asked Questions
Can I mail a 4x6 photo as a postcard?
No. Photos printed on photo paper do not meet USPS standards for postcard stock, which requires a specific thickness and flexibility. Use an envelope and letter-rate postage instead.
What happens if my postcard is too large for the postcard rate?
USPS will treat it as a letter and require $0.82 postage. If you underpaid, the card may be returned or delivered postage-due to the recipient.
Can I use a postcard stamp on a standard letter?
No. A postcard stamp is worth $0.65, which is below the $0.82 letter rate. Your letter would be returned for insufficient postage.
Current Product Examples
If the finished card qualifies for the domestic postcard category, the 100-count 2025 Vibrant Leaves stamp roll is one current format to review. Confirm the live category, count, price, and availability before ordering.
Sources and Scope
- U.S. Postal Service — Postal Explorer — Domestic Mail Manual, sections 101 and 201, physical standards for retail letters and cards.
- U.S. Postal Service — Postal Explorer — Notice 123 Price List, First-Class Mail retail prices, effective July 12, 2026.
Rates apply only when the mailpiece qualifies for the stated category. Weight estimates are planning aids, not a substitute for weighing and measuring the finished piece.