Postal Matter in the United States

US Postal Service Classifications of Postal Matter

Introduction to Postal Matter

Mailable matter in the domestic service is divided into four classes, for which different rates are charged. First-class mail includes letters, postcards, matter wholly or partly in writing, and matter sealed or closed against inspection; second-class mail comprises newspapers and periodical publications; third-class mail (less than 16 oz/170 g) includes books, circulars, matter wholly in print, and proof sheets; and fourth-class mail (domestic parcel post, 16 oz or over) covers merchandise and all matter not covered in the other three classes. Express mail, the newest service, provides overnight delivery for packages of up to 70 lb. Letters and postcards sent by airmail to foreign countries are considered first-class mail, as are parcels sent by air or as registered mail. Additional fees are charged for special delivery or special handling. No airmail category exists for first-class letters within the United States.” (1)

Postal Abbreviations

The full list of U.S. postal abbreviations are posted on the Internet by the U.S. Postal Service at (www.usps.gov/ncsc/lookups/usps_abbreviations.htm).

In addition, the two-letter postal abbreviations for the 50 states are listed in the World Almanac, the front of the National Zip Code Directory, The New York Public Library Reference Guide and probably many other places. You can also get the abbreviation for any particular state by looking at the addresses in most geographically organized directories (e.g., the AALL Directory & Handbook or the State Yellow Book).

Postal Rates

Current U.S. postal rates are posted in the Prices section of the U.S. Postal Service Web site. The USPS also posts historical postage rates and a Postage Price Calculatorfor domestic and international retail prices.

Postal or Zip Codes

United States: You can look up a U.S. Zip Code using the Postal Service’s ZIP Code Lookup. You could also use the National 5-Digit ZIP Code and Post Office Directory, which you’ll find in large libraries and post offices.

You can also look up the zip codes found in each county or city.

Canada: For Canadian postal codes, use the Postal Code Look-Up from Canada Post.

Resources

See Also

• United States Postal Service
• Demographics

Notes and References

1. Information about Postal Matter in the Encarta Online Encyclopedia

Guide to Postal Matter