What is CASS? Coding Accuracy Support System (CASS) is a certification system from the United States Postal Service (USPS) for address validation. A CASS-certified address validation service will standardize your mailing list, update outdated addresses, and verify that addresses are valid and complete. You can try SmartyStreets CASS processing services for free.
As a CASS-certified provider, SmartyStreets offers the following:
Standardization is the process of formatting the address according to USPS standards. This involves things like changing "Avenue" to "AVE" and replacing "#" with "STE" or "APT".
CASS-Certified address validation will attempt to correct misspellings and add required information—such as the ZIP Code, ZIP+4 Code, carrier route, or delivery point—that may be missing.
When addresses change (for instance, if a street name changes), SmartyStreets will compare the given address with a list of addresses that have changed. These addresses will be updated by CASS software using LACSLink (Locatable Address Conversion System). NOTE: This is not the same as "move update" or NCOA processing; those have to do with who lives at an address, which is an entirely different issue.
After the addresses have been standardized, corrected, and updated, they are compared with a list of addresses that the USPS considers valid and complete. This verification ensures that your letter or parcel can be delivered with the information you've provided. Delivery Point Validation (DPV) will also indicate whether or not the address is missing secondary information such as apartment or suite number. CASS processing does not validate the person or business that is at the address, but it does validate whether mail can be delivered to an address.