Accurate Append

Accurate Append provides the most responsive and affordable contact data enhancement and append services in the industry. The company is a technology liaison member of the Open Supporter Data Network with an API supporting the standard. Billions of data points on U.S. voters & consumers to bring contact lists to life. CSV, API, @NationBuilder, OSDI & custom solutions for gnarly data challenges.


Accurate Append's batch and API processes support email append and verification, directory phone append, mobile and cell phone append, and general data and demographic append, as well as real-time form data verification and mailing address updates.


Costs vary based on volume, with a $75 minimum order. Large-scale email and mobile phone appends are priced extremely competitively. Contact Adriel Hampton for a quote.

Who can use it?

Accurate Append's services are commercially accessible.

Open Supporter Data Interface docs introduction