Ask HN: Reverse phone lookup API

A quick Google search brings up Whitepages.com http://developer.whitepages.com/docs

You should have better luck asking questions like this at StackOverflow.com http://stackoverflow.com/search?q=%5Bapi%5D+reverse+lookup

when i worked on a voip pbx product, we used an http api from targusinfo for looking up caller id names to cache and pass to end users.

http://targusinfo.com/industries/dsp/identification/

The industry term for what you're (approximately) looking for is CNAM, a search on that should be fruitful.