Quantity and Sizes

Quantity

For Presorted First Class mail, there is a minimum of 500 pieces of identical weight and contents. For Non Profit and Presorted Standard mail (formerly Regular Bulk), there is a minimum of 200 pieces of identical weight and contents.

Sizes

Postcards
Minimum for Domestic Mail: 3-1/2" high, 5" long and .007" thick
Minimum for International Mail: 3-1/2" high, 5-1/2" long and .007" thick
Maximum: 4-1/4" high, 6" long, and .016" thick

Letter-size Mail
Minimum: 3-1/2" high, 5" long, and .007" thick
Maximum: 6-1/8" high, 11-1/2" long, and .25" thick

Flat-size Mail
Minimum: over 6-1/8" high, 11-1/2" long, and .009" thick
Maximum: 12" high, 15" long, and 3/4" thick

Parcels
Maximum: domestic mail—70 lbs. and 108" in length and girth combined;
International mail—size varies by country and class of mail

Nonstandard-size mail
Domestic First-Class Mail or single-piece Standard Mail and international Letters mail (each weighing 1 oz. or less) is considered "nonstandard" when the mail piece is:

  • more than 6-1/8" high, 11-1/2" long, or 1/4" thick, or
  • square-shaped, or proportionally too high or too long (i.e., its length divided by its height is less than 1.3 or more than 2.5).

A U.S. Postal Service surcharge, in addition to the applicable postage and fees, is assessed on each piece of nonstandard-size mail.