The Coding Accuracy Support System (CASS) enables the USPS to evaluate the accuracy of software that corrects and matches street addresses. 

CASS™ Certification

A service provider that meets all of the stringent USPS accuracy requirements is considered CASS-Certified™.

Why CASS-Certified™ vendors matter

Once an address has been cleaned up, standardized, and verified as deliverable, you can be nearly 100% sure that items sent to that address will be delivered as expected.

For more information regarding the CASS system, visit the USPS website link below: