NCOA stands for National Change of Address. Each time a person or business moves and submits a change of address form to the post office, it is registered in the NCOA database. NCOA address updating service is available from AssociationSphere and is especially useful prior to a mailing to ensure the letters will be delivered to the appropriate address in a timely manner. To request a quote for this service for the records in your database, please contact the support team at [email protected].