What is CASS Certification in Bulk Mailing?

Direct Mail Service

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.