Can I use custom die-cut shapes for postcards that will be mailed?

For standard letter-rate mail, the U.S. Postal Service expects postcards to be rectangular. A fully custom die-cut shape usually does not qualify for standard postcard postage, so it is worth checking before you commit to a design.

• Rectangular rule: standard mailable postcards keep four straight sides and square or gently rounded corners.
• Rounded corners: a small corner radius on an otherwise rectangular card is generally acceptable.
• Non-rectangular shapes: hearts, circles, and other die-cut outlines may need to mail as an enclosure or at a different rate.

Take your proposed size and shape to your local post office and confirm it meets current mailing standards before printing a large run.