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