CASS
According to the USPS®, “The CASS™ system improves the accuracy of carrier route, five-digit ZIP®, ZIP + 4®, and delivery point codes that appear on mail pieces. CASS is offered to all mailers, service bureaus, and software vendors who want to evaluate their address-matching software and improve the quality of their ZIP + 4, CRIS, and five-digit coding accuracy. This process is graded by the United States Postal Service®, National Customer Support Center (NCSC), and the results returned to mailers in order to provide useful diagnostics for correcting deficiencies.”
Certification
Each year, in order to obtain CASS certification from the USPS, software vendors must pass the annual certification test. The test includes all changes for the current annual cycle, as well as, all previous CASS requirements. Changes are intended to improve the accuracy of delivery addresses and subsequently reduce errors associated with mail delivery. The test consists of a file compiled by the USPS with 150,000 addresses and is made up of many different types of addresses and problems. CASS Software is required to correctly process the test file with a minimum 98.5% accuracy.