CASS

CASS is an acronym for Coding Accuracy Support System and is a fundamental building block of Address Quality and accurate mail delivery. CASS helps ensure address matching software can accurately standardize and correct addresses according to USPS guidelines. This process is sometimes referred to as address "coding".

Certification

In order to obtain CASS certification from the USPS, software must pass a certification test for the current CASS cycle. The test includes all changes for the current cycle, as well as, all previous CASS requirements. Changes are intended to improve the accuracy of delivery addresses and subsequently reduce errors and delays associated with mail delivery.

The test is a file compiled by the USPS with 150,000 addresses and is made up of many different types of addresses and problems. The test verifies that various elements of each address have been coded correctly including, ZIP Code, ZIP + 4, Delivery Point, Carrier Route, LACSLink(Locatable Address Conversion System), eLOT (Enhanced Line of Travel), DSF2 (Delivery Sequence File), and RDI (Residential Delivery Indicator). CASS Software is required to correctly process addresses in the test file with a minimum 98.5% accuracy.

FAQ's

Do mailers need to be CASS certified?
  You don't have to be CASS certified yourself to get discounts on postage. Addresses must be processed with CASS certified software. PS Form 3553 should be provided by the software and is required to submit a discounted mailing.
How often do I need to process my address list?
  Addresses must be processed at least every 180 days.