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How Many Stamps Do You Need for a Postcard?

A standard USPS postcard needs one postcard stamp. Learn the current postcard rate and when oversized or square cards cost more.

Direct answer

A standard USPS postcard needs one postcard stamp. The current postcard rate is $0.61. You can use a Forever stamp instead, but it overpays a standard postcard because a current Forever stamp is worth $0.78. Oversized, square, thick, or unusual cards may stop qualifying as postcards and can cost more.

standard postcard = one postcard stamp; nonstandard card = check letter or nonmachinable price

Postcard stamp rules

Standard USPS postcard

One postcard stamp

Must meet postcard dimensions and thickness

Postcard with Forever stamp

Works but overpays

$0.78 stamp value is more than $0.61 postcard rate

Oversized card

May cost letter postage

Large cards can lose postcard pricing

Square card

Often costs more

Shape can create nonstandard handling

Thick, rigid, or embellished card

Check before mailing

Thickness and stiffness can change the price

Postcard price depends on eligibility

The cheap one-stamp answer applies to standard postcards. Greeting-card-style pieces, thick photo cards, square cards, and oversized mailers may need letter, nonmachinable, or other postage instead.

Check a postcard before mailing

  1. 1Confirm the card is rectangular.
  2. 2Measure it against current USPS postcard size limits.
  3. 3Check that it is not too thick, rigid, or embellished.
  4. 4Use one postcard stamp for a standard postcard.
  5. 5Use a Forever stamp or exact additional postage only when the card costs more.

FAQ

Do I need a special postcard stamp?

A postcard stamp is the cheapest correct option for a standard USPS postcard. You can also use other stamps that add up to at least the postcard rate, but a Forever stamp overpays a standard postcard.

Can I use a Forever stamp on a postcard?

Yes. A Forever stamp covers more than the current postcard rate, so it works for a standard postcard but costs more than using a postcard stamp.

Are square postcards more expensive to mail?

Often yes. Standard postcard pricing depends on size, rectangular shape, and thickness. Square, oversized, or unusually thick cards may be priced as letters or nonmachinable mail instead of postcards.

Sources & method

We reviewed these references while writing this answer. Figures are estimates — confirm safety-critical work with a professional. Last updated June 7, 2026.