How to verify a California C-42 septic contractor license in about a minute

Which trade needs which credential

California splits septic work in two, and the split trips up more homeowners than anything else on this site.

• Installation, repair, replacement, drain-field work — CSLB C-42 Sanitation System Contractor. Per CSLB's own classification description, a C-42 contractor performs work involving cesspools, septic tanks, storm drains and other sewage disposal and drain structures, and lays the pipe and hardware for them. This is what the steps below verify.
• Pumping and hauling — not a CSLB classification at all. It is a separate, typically county-level registration program. A pumping-only company will not appear in a CSLB search, and that is normal, not a red flag. Ask a pumper directly about their county registration instead. Tulare County's own septic pages don't publish a registered-hauler list, so this site doesn't name a specific mechanism it can't confirm.

So the first question is: which job is this? A pump-out — ask about county registration. Anything that involves digging, replacing, or fixing the system — verify the C-42. If you're not sure which it is yet, our how we match septic pros page walks through how the two trades divide a typical job.

The check, step by step

1. 1

   Get the license number from the contractor

   Ask for it directly. A licensed California contractor has a license number and should be able to give it to you on the spot — it belongs on their truck, their estimate and their contract. Hesitation is your first data point. If they only give a business name, that works too; the lookup can search by name.

2. 2

   Go to CSLB’s own site, cslb.ca.gov, and open “Check a License”

   Use the Contractors State License Board’s official lookup, not a third-party “license verification” site. CSLB’s tool is free and is the record of truth; anything else is a copy of it, possibly stale.

3. 3

   Search by license number (best) or business name

   The number is exact. A name search can return several similar businesses — a real problem in septic, where “Valley Septic” and “Valley Septic Service” may be unrelated companies. If you search by name, match the address and the personnel to the people you actually spoke with.

4. 4

   Confirm the classification list includes C-42

   The record lists every classification the license holds. For septic installation, repair, replacement or drain-field work you want to see C-42 — Sanitation System Contractor. A C-36 (plumbing) or B (general building) license alone is not a C-42; a contractor can hold several, and many septic contractors also hold C-36 or A (general engineering).

5. 5

   Check the status is “Active” and the expiration date is in the future

   The record shows the license status and its expiration. Anything other than a current, active license — expired, suspended, inactive — means the person cannot legally contract for the work today, whatever they held last year.

6. 6

   Look at the bond and workers’ compensation lines

   The record shows whether a contractor’s bond is on file and whether the business carries workers’ compensation insurance or has filed an exemption. A workers’ comp exemption is legal for a contractor with no employees — but if a crew of three shows up with an exemption on file, ask about it.

7. 7

   Read the complaint and disciplinary section

   CSLB discloses certain complaints and disciplinary actions on the public record. One old resolved item is not a verdict; a pattern is.

8. 8

   Match the name on the license to the name on your contract

   The business name and the personnel (owner, qualifying individual) on the CSLB record should match who is quoting you and whose name is on the paperwork. A license “borrowed” from someone else is a red flag CSLB itself warns about.

Reading the record: what each field means

Classifications

A license can carry several classifications, and septic contractors often hold a few — C-42 with C-36 (plumbing) is common, and some also hold A (general engineering) for the excavation side. What you need to see for septic work is C-42 specifically. A contractor with only C-36, or only a B general building license, is licensed for other work, not for building or repairing your septic system.

Status and expiration

"Active" with a future expiration date is the only acceptable combination. "Expired," "Inactive," "Suspended" and similar all mean the license is not currently valid for contracting, whatever the truck says.

Bond

California requires licensed contractors to keep a contractor's bond on file, and the record shows whether one is. This page deliberately doesn't state the bond amount — confirm the current figure on cslb.ca.gov rather than trusting a number that may have changed. What matters for you is simply that the record shows a bond in force.

Workers' compensation

The record shows either a workers' comp policy or an exemption. An exemption is legal for a contractor with no employees. It is worth a question if the contractor clearly does have employees, because an injury on your property with no coverage can become your problem.

Personnel

Every license has a qualifying individual — the person whose experience the license rests on. The names here should match the business you're dealing with. CSLB itself warns consumers about contractors operating under someone else's license number.

Red flags the record won't show you

• A license number that checks out — for a different business name than the one on the estimate.
• "We don't need a permit for this." Most septic construction and repair in Tulare County needs one through Environmental Health ((559) 624-7400); Kings County for Hanford-area properties. A contractor volunteering to skip it is volunteering you into a problem at resale.
• A quote for drain-field or tank replacement without any mention of the county reviewing the design — the county, not the contractor, decides what can be built where.
• Cash-only, full payment up front, or pressure to sign today. None of these are licensing issues, and all of them are reasons to get a second quote.
• A pumping company that offers to "fix" a cracked tank or a failing field on the spot. That is C-42 work; a pumper doing it without the license is unlicensed contracting regardless of how good the price is.

Beyond the license: three more things worth asking

• Who pulls the county permit, and is it in the quote? A C-42 contractor typically handles the Tulare County application as part of the job. Ask whether the permit fee is included, excluded, or passed through at cost — the county doesn't publish its schedule, so the contractor's answer is the only number you'll get before the work starts.
• Does the county inspect before backfill? Ask the contractor whether Tulare County wants to see the new tank or trenches before they're covered, and whether the schedule allows for it. A contractor who has a ready answer has done this before in this county.
• Who does the pumping? A C-42 contractor repairing a tank still needs it emptied first. Some hold their own county pumper registration; others subcontract a pumper. Either is fine — but know whose truck is coming and whose invoice it's on.

What this site checks, and what it doesn't

Contractors in our network report holding an active C-42 license and current insurance for install/repair work; pumpers report their county registration. We don't independently audit every license on an ongoing basis — and neither does any referral site, whatever the badge says. The one-minute check above gives you exactly the information we'd be looking at, from the source, on the day you need it. Do it before you sign.