How to Build an Annual Insurance Review for Your Plumbing Business

The short version

Most plumbing companies' insurance programs are assembled one emergency at a time: a certificate request, a first hire, a stolen trailer. Each policy was right for the business on the day it was bought. The business then changes — a second van, a backflow certification, the first multi-family repipe, a part-time dispatcher — and nobody tells the policies. The gap between what the business does and what the policies were written for is where claims get denied and audits produce bills.

An annual review closes that gap on a schedule instead of after a loss. It is not complicated: one date, one folder of documents, one list of questions per policy line, one page of answers. The value is in doing the same thing every year so that what changed stands out. This article lays out the calendar, the documents, the questions, the operational changes that matter most for a plumbing contractor, and a one-page template to fill in.

A realistic scenario

This is a hypothetical. A San Diego County plumbing company with five field employees and three vans has carried the same general liability, workers' compensation, auto and equipment policies, with the same broker, for seven years. Renewals are signed when they arrive. During the most recent year the owner added backflow testing and certification as a service line, bought a fourth van in September and put it on his personal policy "until renewal," hired a part-time office assistant who also rides along on Fridays, and started subcontracting trenching to a two-man excavation outfit whose certificate expired in June.

In the spring three things happen in one month. A backflow device the company tested and tagged fails and a commercial kitchen is flooded; the general liability carrier notes that the application still describes the operation as "residential service and repair" and asks questions about the testing work before accepting the claim. The fourth van is in an at-fault accident with the office assistant driving; the personal auto carrier reserves its rights because the vehicle was in business use by a non-listed driver. And the workers' compensation audit assigns the office assistant's full payroll to the plumbing classification, because an employee with any duties beyond clerical work does not qualify for the clerical classification and her payroll cannot be split between the two, and charges premium for the excavation sub's uninsured payroll.

None of this required new insurance. It required someone to notice, once, that the business had changed. The owner's broker would have caught every item in a 45-minute review if the owner had put the backflow work, the van, the assistant and the sub on a single page.

Step 1: Pick the date and tie it to two calendars

The review has to be on a fixed date or it does not happen. Two dates in the insurance year matter:

• Your main renewal date. For most plumbing companies, workers' compensation and general liability renew together, with auto and equipment often aligned. The review belongs about 90 days before that date, so its output becomes the renewal submission; see when should a plumbing contractor start shopping for insurance renewal for the 90/60/30 timeline that follows.
• The X-Mod data date. Your experience modification is calculated by the WCIRB from unit statistical reports your carriers file. The experience period covers three policy years, beginning four years and nine months before the rating effective date and ending one year and nine months before it, so the most recent completed policy year is not in the mod; the three before it are. Each year's data is first valued about 18 months after that policy's inception, and the latest report used in the mod is due no later than one month before the rating effective date. Once a mod is issued, a later change in a claim's value generally flows into the next mod rather than revising the current one, unless closed claims drop below 60 percent of their highest reported combined value, which requires a revision under Insurance Code section 11751.9. The practical consequence: the time to get an open claim closed, a reserve reviewed or a subrogation recovery reported is before the valuation date, not after the worksheet arrives. Ask your broker or carrier for the valuation date of the policy year about to enter your next mod and put a claim review 60 days ahead of it.

If your policies renew on different dates, use the workers' compensation date for the main review and a short check for the others.

Step 2: Assemble the same documents every year

The review is only repeatable if the inputs are. Keep a folder, physical or shared, with:

• Current policies, including every endorsement and the forms schedule, for general liability, workers' compensation, auto, equipment and umbrella.
• Loss runs, five years, every line, requested fresh each year.
• Payroll by employee for the past twelve months with hourly wage, hours and job duties, and a projection for the coming year by classification.
• Vehicle list (year, make, VIN, garaging address, how titled, primary use) and driver list (license numbers, dates of birth, which vehicles).
• Equipment inventory with serial numbers and replacement values, updated for purchases and disposals.
• Subcontractor file: each sub's CSLB license number, certificate, endorsements and expiration dates.
• Major contracts signed during the year and their insurance exhibits.
• Your CSLB license record, printed from the CSLB website on the review date.
• The most recent experience rating worksheet and any WCIRB correspondence.
• Last year's completed review page.

Step 3: List what changed

Before looking at any policy, write down every change in the business since the last review. Underwriters price the operation described on the application; anything not on it is, at best, unpriced and, at worst, excluded. For a plumbing contractor the changes that matter most:

New services. The C-36 classification is broad: it covers water and waste piping, gas piping and gas appliance connections, venting for gases and liquids including vacuum, compressed air and medical gases, water heating equipment including solar, and safety devices such as earthquake valves, backflow preventers and regulating valves. A general liability policy, however, is often underwritten for the subset you described when you applied. Adding gas line work, backflow testing and certification, medical gas, hydro-jetting, trenchless or pipe-bursting sewer replacement, boiler work, or solar thermal is a change to report. Some policies exclude or limit specific operations; some carriers want a supplemental application.

New project types. Moving from service and repair into multi-family, new construction, tract work, or commercial tenant improvements changes the completed operations exposure, and restrictions on those project types are a common classification limitation on contractor general liability policies. See plumbing contractor insurance exclusions you should understand.

People. New employees, changes in duties, a first hire if you had none; see insurance considerations when hiring your first plumbing employee. For workers' compensation, each person's classification depends on duties and, for plumbing work, hourly wage against the WCIRB dual-wage threshold, and the dual-wage split must be supported by time records. An office employee who also does field work does not qualify for clerical classification 8810, which is limited to employees engaged exclusively in clerical work.

Vehicles and drivers. Anything bought, sold, or moved between personal and business use; any new driver; any driver whose record has changed.

Equipment. Purchases above the blanket per-item limit, which usually need to be scheduled; disposals that can come off the schedule.

Subcontractors. New subs, subs whose certificates have expired, and any unlicensed labor.

Entity and ownership. A change from sole proprietor to LLC or corporation changes the named insured and, for an LLC, adds CSLB's $100,000 employee bond and the general liability minimum. Ownership changes also affect experience rating.

Locations. A new shop or yard changes property, equipment and premises exposure.

Step 4: Walk each policy line against the change list

Use the same questions every year. Record the answers on the template below.

General liability

• Does the description of operations on the policy match what we do now, including every service added this year?
• Is completed operations included and unrestricted? See completed operations coverage for plumbing contractors.
• Which exclusions or limitations are on the forms schedule, and do any touch work we now perform (residential, multi-family, subsidence, fungi, pollution, action-over, prior work)?
• Do we have blanket additional insured for ongoing and completed operations, primary and non-contributory, and waiver of subrogation, and do they satisfy the exhibits in this year's contracts? See certificates of insurance and additional insured requirements.
• What is the premium basis, and does the projected payroll or revenue match what we gave the carrier?
• What deductible applies, and to what?

Workers' compensation

• Is every employee in the right classification for their duties and wage, and do the time records support the split?
• Does projected payroll by classification match the policy estimate within a reasonable margin?
• Are the employers' liability limits what our contracts require?
• Were any subcontractors uninsured during the year, and do we have certificates for the rest?
• Has the carrier filed the current certificate with CSLB, with CSLB listed as certificate holder?
• When the experience rating worksheet arrived, did the claims and payroll match our records? Our guide to reading a California experience rating worksheet covers what to check, and seven common issues to review in a plumbing contractor's X-Mod lists what most often goes wrong.

Commercial auto

• Is every vehicle used in the business on the commercial policy, including anything titled to an owner?
• Is every person who drives a company vehicle a listed driver, and have records been run?
• Is hired and non-owned liability on the policy?
• Do physical damage limits reflect what a built-out van costs to replace?

Tools and equipment

• Does the schedule match the inventory, including this year's purchases?
• Is anything above the blanket per-item limit unscheduled?
• Does the policy cover equipment in vehicles overnight, at jobsites and in the shop, and what is the theft deductible?

Umbrella / excess

• Do our contracts require limits above what the primary policies carry?
• Does the umbrella sit over general liability, auto and employers' liability, with no gaps in the underlying limits it requires?

Step 5: Subcontractor certificate audit

Go through the subcontractor file sub by sub. For each: license number checked on the CSLB website on the review date; general liability and workers' compensation certificates current for the whole period they worked; the endorsements you need (additional insured, primary, waiver) attached; expiration dates on the calendar for the coming year. Subs without evidence of coverage are charged to you at audit, and the workers of an unlicensed sub are generally treated as your employees for workers' compensation purposes. See are plumbing subcontractors covered by your insurance?.

Step 6: CSLB record check

Print your license record from the CSLB website and confirm: the $25,000 contractor's license bond is active and the surety is current; the workers' compensation policy on file is the current one, or the exemption is still valid (and remember that under current law the exemption option ends for all licensees on January 1, 2028); any bond of qualifying individual is in place; and, for an LLC, the $100,000 employee bond and the general liability insurance of at least $1,000,000 (plus $100,000 per person of record above five, to $5,000,000) are on file. Check it yourself rather than waiting for a letter: failure to maintain required workers' compensation coverage results in suspension, and work performed while suspended is treated as unlicensed. See the C-36 license guide for each item.

Step 7: Contract requirements and limits adequacy

Read the insurance exhibits from the contracts you signed this year and the ones you expect to bid next year. Note the highest limits required, the endorsements required, and any carrier rating requirement. Then ask whether your limits are adequate on their own terms: what is the largest plausible completed operations loss from the kind of building you work in most? For a company that has moved into multi-family or commercial kitchens, the answer is different from a residential service shop, and this is the question that decides whether to raise limits or add an umbrella.

A one-page review template

Fill it in once a year, keep every year's copy, and hand the current one to your broker as the start of the renewal.

Practical takeaway

Choose the date, 90 days before your main renewal, and a second short check ahead of the X-Mod valuation date. Gather the same documents. Write down every change before you open a policy. Ask the same questions of each line and write the answers on one page. Audit the subs, print the CSLB record, read the contracts, and decide what to change. Then give the page to your broker and start the renewal with the facts already assembled.

Done that way, the San Diego company in our scenario would have had backflow testing added to the general liability application in the fall, the fourth van and the office assistant on the commercial auto policy, a decision made about her Friday ride-alongs, either ending them so her payroll qualifies as clerical or budgeting her payroll in the plumbing classification, and the excavation sub's expired certificate chased in July. If you would like a licensed producer to walk through the template with you the first time, send your questions through our contact page.