USPS Office of Inspector General

The Postal Service has more than 10,000 prices contained in a 1,800-page customer manual known as the Domestic Mail Manual (DMM). The DMM provides individual and commercial mailers with information about postal services and standards for both domestic and international mailings. The Price List, also known as Notice 123, contains domestic and international retail and commercial prices for all postal products and services.

The Postal Accountability and Enhancement Act of 2006 (PAEA) changed the way the Postal Service sets rates. It divided postal services into two broad categories: market dominant (mailing services) and competitive (shipping services). Market dominant products constitute about 90 percent of postal revenue. They include First-Class Mail, Standard Mail, Periodicals, and some Package Services. Products such as Priority Mail, Express Mail, and bulk Parcel Post are considered competitive. The PAEA placed a cap on price increases for market dominant products.

Stamp prices are traditionally in whole cent increments. That means it is difficult to target a particular percentage increase. For instance, a one-cent increase on the 42-cent stamp would have been 2.4 percent; while the two-cent increase was 4.8 percent.