For mail sent through the U.S. Postal Service, postcards must be at least 3.5 inches high by 5 inches long by 0.007 inch thick and no bigger than 4.5 inches high by 6 inches long by 0.016 inches thick. The standard-size ... More » Business & Finance Mail & Shipping Postal Services

A standard postcard measures 6 inches wide by 4.125 inches high, which is the maximum size allowed by the United States Postal Service to qualify for first-class mail postcard rates. The USPS postcard minimum size is no ... More » Business & Finance Mail & Shipping

Most commercially-produced postcards measure approximately 4.21 inches by 5.47 inches. Less commonly, smaller postcards are typically 3.5 inches by 5.5 inches, close to the minimum size the USPS allows. More »

The differences in U.S. Postal Service shipping prices are due to the size of the package, the type of service the person is choosing and the distance to the mail's destination. The weight of the package also plays a rol... More »

The Global Forever stamp can be used to mail a postcard or 1-ounce letter-size letter anywhere in the world by First Class Mail International delivery, according to the U.S. Postal Service. In 2014, a Global Forever stam... More »

The average size of a standard postcard is 4 inches high by 6 inches wide. In the United States, a postcard of this size can be mailed under a special First-Class rate. More »

Recipients are advised to mark unwanted mail as "refused" and return it unopened to the U.S. Postal Service within a reasonable amount of time. Following this procedure excuses the recipient from paying for new postage f... More »