What Insurance Does a Plumbing Contractor Need in California?

The short version

Two things are mandatory for almost every California plumbing contractor. If you have even one employee, you must carry workers' compensation insurance. To hold a CSLB license at all, you must post a $25,000 contractor's license bond. If your company is an LLC, add a $100,000 bond for the benefit of your workers and general liability insurance of at least $1,000,000.

Everything beyond that is "required" only in the sense that the people who hire you will not let you on the job without it. For a working plumbing company, that list is general liability, commercial auto, tools and equipment coverage, and, as you grow, an umbrella. This article walks through each one, what it does for a plumbing operation specifically, and how to decide what you need this year versus next.

A realistic scenario

A two-truck repipe and service company in Sacramento has been running for four years. The owner carries general liability because a property manager asked for a certificate the first month, and workers' comp because he has three plumbers on payroll. The vans are on his personal auto policy because the first one was his personal truck and the second just followed. Tools are not insured at all.

In one quarter three things happen. A journeyman slips in a crawlspace and needs knee surgery. The newer van is rear-ended at a light with $9,000 of press tools, a sewer camera and a jetter trailer hitch behind it. And a tenant in a six-unit building reports that a supply line the company replaced two months ago let go overnight and soaked the unit below.

The workers' compensation claim is paid, and it will sit in his X-Mod for three years. The van claim is where the trouble starts: a personal auto carrier can deny or rescind coverage when a vehicle is used in a business the policy did not contemplate, and even when it pays for the van, personal auto does not cover the tools inside it. The water claim is likely a covered general liability loss — the damage was to someone else's property, caused by completed work — but the carrier will look closely at how the fitting failed and whether the policy has any exclusion that applies.

None of these is exotic. They are the three most common claim types in the trade, and the gaps show up exactly where coverage was bought by accident instead of on purpose.

What the state actually requires

Workers' compensation

California Labor Code section 3700 requires every employer with one or more employees to carry workers' compensation insurance (or qualify to self-insure, which is not realistic for a small contractor). The Department of Industrial Relations puts it simply: if a business employs one or more employees, it must satisfy the requirement of the law.

For licensed contractors, CSLB enforces this at the license level. You must either have a policy on file with CSLB or an exemption certifying that you have no employees. Five classifications — C-8 concrete, C-20 HVAC, C-22 asbestos abatement, C-39 roofing and C-61/D-49 tree service — must carry workers' compensation regardless of whether they have employees. C-36 plumbing is not on that list today, so a plumber with no employees may still file an exemption.

Two deadlines matter here:

• Your exemption dies the day you hire. An exemption on file becomes invalid the moment you hire an employee subject to California workers' compensation law, and CSLB must receive proof of coverage within 90 days of that hire. Working with an invalid exemption exposes you to license suspension and to the uninsured-employer penalties described in our C-36 requirements guide.
• January 1, 2028. Senate Bill 216 originally required every licensed contractor, with or without employees, to carry workers' compensation by January 1, 2026. Senate Bill 1455, signed in 2024, pushed that date to January 1, 2028. If you are a sole operator planning around the old date, you have more time than you thought; if you were hoping the requirement would go away, it has not.

The contractor's license bond

Every active CSLB licensee must have a $25,000 contractor's license bond on file. A separate $25,000 bond of qualifying individual is also required if your license is qualified by a responsible managing employee (RME), or by a responsible managing officer (RMO) who owns less than 10 percent of the corporation's voting stock. The bond is not insurance for you: it protects consumers and workers harmed by a violation of the license law, and the surety expects to be repaid if it pays out.

Additional requirements for LLC licensees

If your plumbing company is a limited liability company, Business and Professions Code sections 7071.6.5 and 7071.19 add two requirements that corporations and sole proprietors do not face:

• A $100,000 surety bond for the benefit of employees and workers.
• General liability insurance with a cumulative limit of at least $1,000,000 for licensees with five or fewer personnel of record, plus $100,000 for each additional person of record, up to a maximum required limit of $5,000,000.

This is the one place California law tells a contractor to buy general liability. For every other entity type, the state is silent and the market speaks instead.

What the market requires

General liability

A commercial general liability (CGL) policy pays, on your behalf, for bodily injury and property damage to other people arising from your operations and your completed work, subject to the policy's terms and exclusions. For a plumber, that is the flooded unit downstairs, the gas line hit that damages a neighbor's wall, the customer who trips over your drain snake. It does not cover injuries to your own employees (that is workers' compensation), damage to your own tools and vehicles, or the cost of redoing your own faulty work.

Many general contractors, property managers, homeowners' associations and commercial customers require a certificate showing specific limits (often $1,000,000 per occurrence and $2,000,000 aggregate), often with additional insured status and primary/non-contributory wording. See Does general liability cover water damage caused by a plumber? for how the policy responds to the most common plumbing claim.

Commercial auto

Service vans are the most visible part of a plumbing business and, after workers' compensation, usually the second most frequent source of claims. A commercial auto policy covers liability to others when your vehicles are driven for work, and can cover physical damage to the vehicles themselves. If a vehicle is used in the business, it should be on a commercial policy even if it is titled to the owner personally; personal auto policies commonly exclude or limit business use, and a denied claim after a serious accident can end a small company.

Two commercial-auto details plumbers tend to miss: hired and non-owned auto liability, which protects the company when an employee runs to the supply house in their own car, and physical damage limits that reflect what a built-out service van actually costs to replace.

Tools and equipment (inland marine)

The press tools, sewer cameras, locators, jetters and hand tools that ride in a plumbing van can add up to tens of thousands of dollars per truck, and none of it is covered by the auto policy. Contractor's equipment coverage, usually written on an inland marine form, insures that equipment against theft and damage wherever it is: in the van, at the jobsite, or in the shop. Smaller items are often covered on a blanket basis up to a per-item limit; higher-value items like a trailer-mounted jetter are scheduled individually.

Umbrella / excess liability

As you take on commercial work, contracts often ask for higher liability limits than a primary policy provides, commonly in the millions. An umbrella policy sits above your general liability, auto liability and employers' liability and provides those higher limits more economically than raising each underlying policy. Most companies do not need one in year one; most companies doing commercial or multi-family work need one by the time they are bidding it.

How the pieces fit together

The practical rule: the state's list is the floor. The size of your biggest plausible loss is the ceiling. A one-truck drain cleaning shop and a 15-truck repipe company both have the same legal minimums; what they can absorb is completely different.

Practical takeaway

Start with the mandatory items and make sure they are not just purchased but in force and on file — the CSLB record is what an inspector, a GC's compliance department or an opposing lawyer will check. Then buy general liability and commercial auto regardless of entity type, because the first customer who asks for a certificate will not care that the state did not require it. Add equipment coverage when the tools in a van exceed what you could replace out of pocket, and an umbrella when a contract asks for it.

Review the whole program once a year, before renewal, with your payroll, vehicle list and equipment inventory in hand. Coverage bought one piece at a time, as this year's problem demands, is how the Sacramento company in our scenario ended up with a flooded unit covered, a wrecked van in dispute and a trailer full of tools uninsured.