FullContact now supports lookup by phone number in addition to email address, Twitter handle, and Facebook username. You can think of FullContact phone lookup as “Social Caller ID”; you pass us a phone number, we resolve the identity and return all of the relevant contact information associated with that person.
Querying for contact information by phone number is as simple as passing the phone paramater to the Person endpoint. Phone number queries will return the same type of response as any other query to the Person endpoint, just specify your desired response format.
Match rates will be lower in comparison to email, Twitter, or Facebook username queries, so for the time being query on the other parameters if you have them, and rely on phone number as a last resort. Over time, as we add more phone numbers to our system, the match rate on phone number lookups will improve.