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™.

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:

http://zip4.usps.com/ncsc/addressservices/certprograms/cass.htm