National Change of Address (NCOA)
The National Change of Address (NCOA) program makes change-of-address (COA) information available to mailers to help reduce undeliverable or duplicate mailpieces. Input address information provided by a mailer to the NCOA licensee is first standardized to conform to USPS requirements, including the ZIP+4 code. NCOA helps reduce undeliverable-as-addressed mail by correcting input addresses prior to mailing.