Pursuant to a legislative requirement, GAO reviewed the U.S. Customs Service's efforts to improve controls over mail collection of assessed duties and fees.

GAO found that Customs: (1) assessed $26 million in duties and processing fees in fiscal year 1990, and collected about $24 million through the U.S. Postal Service; (2) reported that about $10 million in duties and fees was delinquent; (3) identified several internal control problems regarding collection follow-up, collection deposits, loss and theft controls, and its system for tracking assessments; (4) reported that such problems resulted in inaccurate billings, collection backlogs, and deposit delays; (5) began to overhaul its system for assessing, depositing, and accounting for duties and processing fees on mail imports in 1989; (6) was developing new automated systems to replace manual processes and to provide better controls, accountability, and more accurate information; (7) expected that the new systems will enable it to more effectively monitor mail collections and improve its ability to follow up on outstanding assessments and promptly deposit collections; and (8) planned to complete those improvements by the end of December 1991.