My contractor has gone quiet and stopped answering, how do I track him down to sue him?

Start with his license record through the CSLB's public license lookup tool, which lists his address of record along with the identity of the company that issued his surety bond, the bonding company that stands behind his license financially. If your contractor operates as a corporation or an LLC rather than as a sole proprietor, the California Secretary of State's business search tool will show the registered agent designated to receive legal service on the entity's behalf, a required point of contact specifically for situations like this.

If it turns out your contractor has genuinely vanished and can't be located through either of these channels, the bond claim against his surety company often becomes more practically important than the lawsuit itself, since recovering against the bond doesn't require you to personally track down and serve the contractor the way a small claims case does.