NCOA database is the National Change Of Address database managed by the USPS (United States Postal Service). Mailers run an National Change Of Address process on their mailing lists to maintain address accuracy, lower mailing costs, and increase open rates. Every citizen is, by law, required to report any change in his or hers address. National Change of Address is a data set which consists of about 160 million changes of address records. They consist of addresses of individuals, families or companies who have filled out a form to let them know that hey have changed your address. National Change of Address exists in order for people to report any changes of address in their life. If one moves to another town, changes homes for some reason, moves to another country etc, they are obligated to report their change of address. They do so by filling out a form. Even though National Change Of Address is a part of the United States Postal Service, not all post offices are included in this service. Many post offices have their own systems for change of address. Companies who are involved with this service, like credit card companies, may receive incorrect information, quite often.