Do I need commercial auto insurance for my plumbing van?

Yes, in practice: if a van or truck carries your tools, your people or your company name to jobs, it should be on a commercial auto policy. Nothing in the CSLB license rules tells you which kind of auto policy to buy, and the customers who hire you rarely check. The reason is the carrier. Personal auto policies are underwritten for commuting and errands, and most of them exclude or limit coverage for a vehicle used in a business, especially one with a ladder rack, a built-out interior and a crew behind the wheel. A personal carrier that learns at claim time that the van is a plumbing truck may deny the claim, pay a reduced amount or decline to renew.

A commercial auto policy, subject to its terms, exclusions and endorsements, does three things a plumbing company needs. It covers your company's liability to other people when a vehicle is driven for work. It can cover physical damage to the van itself at a value that reflects the build-out. And it can be endorsed for hired and non-owned autos, employee drivers and the trailers you tow. It does not cover the tools inside the van (that is inland marine coverage) or injuries to your own employees (that is workers' compensation).

If the van is titled in your personal name but used for the business, that does not change the answer. Tell your producer how each vehicle is titled and used so the policy is written to match.