How big can a postcard be to use a postcard stamp?

Answer:

Postcards - $0.28
Size limits:

  • Minimum: 3-1/2 inches high by 5 inches long by 0.007 inch thick
  • Maximum: 6 inches long by 4-1/4 inches high
  • Additional postage required for larger postcards

Postcards that are over 4-1/4 inches high X 6 inches long X 0.016 inch thick are considered oversized. They will be charged as a letter or large envelope depending on the size.

This was copied directly from the USPS web site:

http://www.usps.com/prices/first-class-mail-prices.htm

First answer by ID2799206555. Last edit by ID2799206555. Question popularity: 1 [recommend question].