The CASS system improves the accuracy of carrier route, five-digit ZIP®, ZIP + 4®, and delivery point codes that appear on mailpieces. 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.

CASS enables the Postal Service™ to evaluate the accuracy of address-matching software programs in the following areas: (1) five-digit coding, (2) ZIP + 4/ delivery point (DP) coding, (3) carrier route coding, (4) DPV®, (5) DSF2®, (6) LACSLink® (7) eLOT® and (8), RDI™ products. CASS allows vendors/mailers the opportunity to test their address-matching software packages and, after achieving a certain percentage of compliance, to be certified by the Postal Service. CASS does not measure the accuracy of ZIP + 4 delivery point, five-digit ZIP, or carrier route codes in a mailer's existing files. CASS enables mailers to measure and diagnose internally written, commercially-available, address-matching software packages. The effectiveness of service bureaus' matching software can also be measured.

There are two stages in the CASS process: Stage I, which is optional, and Stage II, which is required for certification.

STAGE I - A Test With Answers

CASS Stage I is a self-test that helps developers measure and diagnose the performance of their address-matching software when it is applied to a CASS test address file. The Stage I results assist developers with software debugging and troubleshooting in preparation for Stage II of the CASS certification process. The CASS file contains approximately 150,000 test addresses extracted from the City State and ZIP + 4 files with samples of all types of addressing used around the country. (Some test addresses have been changed for test purposes, and not all records have valid ZIP + 4 codes or valid addresses.)

Customers can evaluate the accuracy of their address-matching software by applying the correct carrier route, five-digit, and ZIP + 4 codes and by comparing the applied codes with the correct codes provided by the Postal Service. The results of Stage I processing are not reviewed by the NCSC and have no effect on CASS certification.

The Stage I file can be downloaded electronically from the Rapid Information Bulletin Board System (RIBBS) website at http://ribbs.usps.gov/files/cass. For more information on downloading Stage I files from the Internet, contact the CASS Department at 800-642-2914.

STAGE II - A Test Without Answers

CASS Stage II is graded by NCSC and is used to evaluate address-matching software performance by processing a test address file. The CASS Stage II file contains approximately 150,000 test addresses that are extracted and presented in the same makeup and mixture as Stage I-only no answers are provided. Customers use their address-matching software to apply the correct codes.

Match rates using CASS Certified™ software vary greatly depending on address hygiene, the quality of addresses used, and the timeliness of the customer database update applications. An address with an incorrect five-digit ZIP™ Code, ZIP + 4 code, carrier route code, or an address with no ZIP + 4 code or failure to process using DPV or LACSLink can contribute to delays in processing mail.

To be CASS Certified, participants must pass with a minimum score of 98.5% for ZIP + 4, carrier route, five-digit and LACSLink. 100% for delivery point coding, eLOT, DPV, RDI and Perfect Address. CASS certification is valid until the end of the current annual period (i.e., from August 1 of one year through July 31 of the next). To remain CASS certified for each annual period, developers must reapply for certification and meet the minimum accuracy requirements during Stage II testing. Certified vendors who wish to be listed are published in the CASS/MASS Certified Products Guide located at http://ribbs.usps.gov/files/vendors.