Postcard Stamps: 2026 Rates and Rules
Current Domestic Postcard Rate
At the rate effective July 12, 2026, a qualifying domestic single-piece postcard costs $0.65. A valid Postcard-category stamp covers that amount. The word “postcard” on packaging does not control classification; the finished mailpiece must meet the physical standards.
Postcard-Rate Dimensions
| Measurement | Standard |
|---|---|
| Length | At least 5 inches and no more than 6 inches |
| Height | At least 3.5 inches and no more than 4.25 inches |
| Thickness | At least 0.007 inch and no more than 0.016 inch |
| Shape | Rectangular and otherwise eligible for postcard pricing |
Can a Postcard Stamp Be Used on a Letter?
Yes, its current $0.65 value can contribute toward letter postage. It is not enough by itself for a qualifying $0.82 one-ounce stamped letter, but additional valid postage can be added to meet the required total. The problem is insufficient value, not that the stamp becomes forbidden on a letter.
Photos and Oversized Cards
A 4-by-6-inch photograph is not automatically eligible or ineligible. It must function as the actual mailpiece and meet material, thickness, flexibility, shape, address, and other applicable requirements. A card larger than the postcard maximum may qualify as a letter if it stays within letter standards; depending on its dimensions, rigidity, thickness, and construction, another category can apply. Measure the completed piece instead of assigning every oversized card the letter rate.
What Happens if Postage Is Short?
Handling can vary with the mailpiece and circumstances. It may be returned, delayed, delivered postage due, or otherwise handled under postal rules. Do not promise that it will always be returned.
Frequently Asked Questions
Can I mail a 4-by-6 photo as a postcard?
Possibly. Confirm that the photograph as prepared meets postcard material, thickness, shape, addressing, and machinability requirements.
What if a card is larger than the postcard maximum?
Reclassify the completed piece. It may qualify as a letter or another mail category depending on all dimensions and physical characteristics.
Can I use a Postcard stamp on a standard letter?
Yes as partial postage. Add enough valid postage to meet the letter's required amount.
Will an underpaid postcard always be returned?
No single outcome is guaranteed. It may be returned, delayed, or handled as postage due.
After confirming that the mailpiece meets postcard requirements, compare available postage stamps for the amount due.
Sources and Scope
- USPS Domestic Mail Manual 101 for postcard and letter physical standards.
- USPS Notice 123 for the current postcard and letter prices.
- USPS Postage Price Calculator for a specific mailpiece.
Examples apply to domestic retail mail and must be checked against the completed piece.