"Phone Append" Refers to a process that involves adding phone numbers to an existing database. An example of a phone append in practice would be the enhancement of a company's customer files. Companies often collect basic information on their clients such as business names and addresses. A phone append process takes the information they have, matches it against a larger database of business data, allowing them to add the missing phone number to the database, or in many cases, update the phone numbers already on file in the event of a change.
The NAICS Association offers a wide range of Data Append Services including Phone Appends, NAICS & SIC Code Appends, and More.