Postcard Mailing Specifications

Shape

• To qualify for postcard rates and services, the post office requires that the card you send must be rectangular in shape. While you're certainly free to exercise your creativity and design cards that are circular, square or another odd shape, you'll lose the benefits of the postcard rate.

Measurements

• Postal requirements indicate that "true" postcards must be at least 3 1/2 by five inches, and their thickness has to be at least 0.007 inch. Your postcard can be no more than 4 1/4 inches high, six inches long, and 0.016 inches thick to qualify for the lowest postcard rate.

Oversized Cards

• You do have the option to creat postcards that are larger than the above-mentioned measurements. If you do, your card will be considered oversized and the postage rate will be the same as that for a letter or possibly a large envelope, depending on its size.

Additional Optional Services

• In addition to regular mail delivery, the post office gives you the option to receive proof of mailing for your postcard. This service is called a Certificate of Mailing. You can also opt to send your card via certified mail, a service that provides you with a mailing receipt and the ability to pull up delivery information online.

Postage

• Postage for postcards is the least expensive of any rate offered by the post office. There are special postcard stamps available. Consult the post office or visit its website to obtain current rates, as they change all the time.