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.