Postal Service

In response to a congressional request, GAO conducted a statistical survey of the Washington, D.C., and the Cincinnati/Dayton, Ohio area to determine the U.S. Postal Service's (USPS) error rate in computing postage on individual letters and parcels that were weighed, specifically: (1) the nature and extent of postage errors; and (2) whether scale maintenance procedures affected the accuracy of postage paid.

GAO found that: (1) postage calculations were accurate most of the time; (2) of the 3,001 pieces of mail sampled in Washington, D.C., 3.4 percent had incorrect postage charges; (3) of the 2,924 pieces of mail sampled in the Cincinnati/Dayton, Ohio area, 1.9 percent had incorrect charges; (4) postal employees' use of incorrect rate information and inaccurate scales, as well as misread scales, resulted in overcharges and undercharges; (5) customers caused some postage errors by affixing too much postage to their mail before submitting it to the postal clerk; (6) 13 percent of the scales were inaccurate; (7) USPS is installing electronic scales to ensure greater accuracy in postage rates; and (8) as of May 1986, USPS had distributed certified test weights to 90 percent of the retail offices to test scales daily for accuracy.