Implementation of the Nine-Digit Zip Code; Hearing before the Subcommittee on Civil Service, Post Office, and General Services of the Committee on Governmental Affairs United States Senate Ninety-seventh Congress First Session on S. J. Res 11, S. 539, and S. 678 February 24 and April 29, 1981

iv, 120, [1] pages. Wraps. Tabular Data. The 1981 Senate hearings regarding the implementation of the nine-digit ZIP code (ZIP+4) were marked by intense debate over automation, costs, and mandatory versus voluntary usage. The hearings, primarily held before the Subcommittee on Civil Service, Post Office, and General Services, aimed to address public and Congressional concerns that the system was premature and overly burdensome. A major focus was ensuring the new, longer code would be voluntary, specifically for residential users, to alleviate public fear of forced compliance. Postmaster General Bolger testified that he supported making it voluntary, except for bulk mailers seeking discounts. Critics in the Senate, such as Senator David Durenberger and Senator Roger Jepsen, argued that the system was not fully tested, might increase costs, and that the public did not want it. The program was designed to cut costs through automated mail sorting using optical character readers (OCRs). In April 1981, Congress considered legislation to block the June 1, 1981 implementation date proposed by the Postal Service, with leaders calling for a cost-benefit analysis. Despite the contention, the Senate moved forward with the program, with the legislative battle continuing through the end of the year, eventually leading to the authorization of the program by late 1981, with full implementation planned for subsequent years. The hearings highlighted the transition from manual to automated mail processing and the friction caused by requiring the public to adopt a more detailed addressing system. The nine-digit zip code (ZIP+4) was introduced by the USPS in 1983 to improve mail sorting automation and speed up delivery. It adds a four-digit suffix to the original five-digit code, identifying specific geographic segments?such as a city block, apartment building, or individual high-volume receiver. The first five digits define the region and local post office. The added +4 indicates a sector (several blocks) and a segment (one side of a street). The system allows automated machinery to sort mail to smaller, more precise delivery areas, reducing manual handling. While proposed earlier, the extended code was officially introduced in 1983. Initial uptake was slow due to a, at the time, small incentive for large-scale mailers. It provided increased accuracy, faster delivery times (sometimes up to two days faster), and reduced costs for bulk mailers. While not mandatory for citizens, it is heavily used by businesses for address verification, mailing efficiency, and better logistical analytics. The system evolved from the original 1963 five-digit Zone Improvement Plan (ZIP) to handle growing mail volumes.…