What is the Difference Between NCOA and CASS?

NCOA

NCOALink or NCOA (National Change of Address) is a data set containing approximately 160 million permanent change-of-address records filed with the United States Postal Service® in the last 48 months. This list consists of names and addresses of individuals, families, and businesses who have filed a change of address.

In other words, consumers will fill out a change of address form online or at their local Post Office. As a result, USPS will apply that move and mail will now be forwarded to their new address.

CASS Certification

Before processing your NCOA update, TrueNCOA must first verify, validate, and perform hygiene on your input records according to USPS standards. The USPS Coding Accuracy Support System (CASS) corrects and standardizes addresses, adds missing address information such as ZIP codes, cities, and states to ensure the address is complete, performs delivery point validation to verify whether or not an address is a deliverable address, and checks against the USPS Locatable Address Conversion System, updating addresses that have been renamed or renumbered. Because this process saves the post office time and money due to reduced sorting and undeliverable mail, mailers who use it can qualify for bulk mailing discounts. Please see the "About NCOA" section of our FAQ for additional information regarding the NCOA process.

An example of what CASS software will correct in an address

Input

1010 Lake
Oake park IL

Output

1010 Lake St
Oak Park IL 60301-1102

It corrects city name, address street suffix, ZIP code, and ZIP+4 add-on, and it identifies the address as a business. You can read more about identifying Residential vs. Business addresses here.