California C-36 Plumbing License Requirements (2026)

The Class C-36 Plumbing Contractor license issued by the California Contractors State License Board (CSLB) authorizes a business to provide a means for a supply of safe water and the proper disposal of fluid waste in residential, commercial, and industrial structures throughout California. The applicant must document four years of journeyman-level plumbing experience, pass the two-part PSI-administered examination (Law and Business plus the C-36 Trade exam), file a $25,000 surety bond, and complete the CSLB Issuance Unit packet before the license is issued.

The Licensing Authority

Contractors State License Board (CSLB) is the statutory authority responsible for issuing and enforcing this license under California Business & Professions Code §7000 et seq. (Contractors State License Law). The CSLB licenses and regulates contractors in 44 license classifications, investigates consumer complaints, enforces contractor license law, and prosecutes unlicensed activity through administrative, civil, and criminal action.

Official portal: https://www.cslb.ca.gov/
Address: 9821 Business Park Drive, Sacramento, CA 95827 (mailing: P.O. Box 26000, Sacramento, CA 95826)
Phone: (800) 321-CSLB (2752) — in California; (916) 255-3900 — outside California

Baseline Eligibility

The applicant must be at least 18 years of age and possess a valid Social Security Number or Individual Taxpayer Identification Number (ITIN). No California residency requirement. Out-of-state applicants may apply.

Good moral character

Applicants must disclose any prior criminal conviction. CSLB conducts a criminal background investigation under Cal. B&P Code §480 and may deny licensure for offenses substantially related to the qualifications, functions, or duties of a contractor.

Background investigation

Mandatory fingerprinting through Live Scan (in-state) or hard cards (out-of-state). Results are reviewed by both the California Department of Justice and the Federal Bureau of Investigation.

Disqualifying conditions

Felony convictions substantially related to construction or financial responsibility
Prior license revocation in California or any other jurisdiction
Outstanding court-ordered restitution to a contractor or homeowner

Experience and Education Requirements

The experience bar is 4 years of journeyman plumber, foreman, supervising employee, or contractor, and it must be backed by verifiable records — typically payroll, tax, project, or supervisor documentation covering the claimed period.

Accepted proof of experience or eligibility

Certification of Work Experience (CSLB form 13A-11), signed under penalty of perjury by a qualified verifier
W-2 statements, pay stubs, and tax returns documenting the four-year period
Apprenticeship completion certificate from a state-approved plumbing apprenticeship program

Education substitution

Up to three of the four years may be credited from accredited technical training, an approved plumbing apprenticeship, or post-secondary plumbing coursework.

The Licensing Examination

Testing is handled by PSI Services LLC (under contract to CSLB). The applicant has to pass each part listed here before the credential is granted:

Law and Business — 115 questions, 210 minutes, passing score 72%
Trade — Plumbing (C-36) — 115 questions, 210 minutes, passing score 72%

Examination fee: Bundled with the $450 application fee; no separate examination fee for the first sitting.

Retake policy: Applicants who fail an examination may reschedule for a fee. The application remains valid for 18 months from the date of acceptance.

Financial Security and Insurance

Before the license is issued, the applicant must file a $25,000 contractor license surety bond in the form prescribed by the CSLB.

General liability

No statutory minimum for sole proprietors and corporations, but commercial general liability is required for limited liability company (LLC) licensees in the amount of $1,000,000 per occurrence (and an aggregate policy limit increased by $100,000 for each additional employee, up to a maximum of $5,000,000).

Workers' compensation

Workers' compensation insurance is mandatory for any licensee with one or more employees. Sole-owner licensees with no employees may file a Workers' Compensation Exemption Certification; certain license classifications cannot claim exemption.

Additional financial requirements

LLC applicants must additionally maintain an LLC employee/worker bond of $100,000 to protect employee wages and fringe benefits.

Fee Schedule

Fee	Amount
Application (non-refundable)	$450
Initial license — sole owner	$200
Initial license — non-sole owner	$350
Renewal (every 2 years)	$450
Fingerprinting (DOJ + FBI)	$49

License Renewal

The California Class C-36 — Plumbing Contractor must be renewed every 2 years. The fee to renew is presently $450. Active sole-owner licenses renew every two years for $450. Non-sole-owner licenses renew for $700. Inactive licenses renew for $300 (sole) or $500 (non-sole). Renewal notices are mailed approximately 60 days before expiration. CSLB does not impose a continuing-education requirement, although the contractor is responsible for staying current on changes to the California Building Standards Code and the trade-specific code that governs the license classification.

Downloadable Asset

2026 California Plumber License Roadmap (PDF) — a printable step-by-step checklist for the application process.

Download the PDF roadmap →

Reciprocity Map

California grants no NASCLA reciprocity for this classification.

Reciprocal State	Accepted Exam	Conditions
Arizona	Trade exam waived	Active C-36 holder for 5 of past 7 years; same classification.
Nevada	Trade exam waived	Active C-36 holder for 5 of past 7 years; same classification; passes Nevada Law & Business.
Utah	Trade exam waived	Active C-36 holder for 5 of past 7 years; same classification; passes Utah Business & Law.

California does not accept the NASCLA Accredited Examination for the C-36 Plumbing classification.

Weighing more than one jurisdiction? The national hub compares Plumber license requirements in every state — exam, bond, fee, and experience thresholds side by side.

The Licensing Roadmap

Form your business entity. Register the business with the California Secretary of State if operating as a corporation, LLC, or partnership.
Document four years of journeyman plumbing experience. Complete the Certification of Work Experience and gather W-2s, pay stubs, and apprenticeship records.
File the Application for Original Contractor License. Submit Form 13A-1 with the $450 non-refundable application fee, specifying the C-36 classification.
Receive the Notice to Appear for Examination. PSI mails a Notice to Appear with scheduling instructions for both the Law & Business and the C-36 Trade examinations.
Pass both examinations. Both portions must be passed with a minimum score of 72%. The C-36 exam covers planning and estimating, underground and rough-in systems, finish plumbing installations, gas piping and water-heating equipment, and service and maintenance.
Submit fingerprints (Live Scan or hard cards). Pay the $32 California Department of Justice processing fee and the $17 FBI processing fee.
File the contractor bond and proof of insurance. File the $25,000 contractor surety bond, the workers' compensation certificate (or exemption), and (for LLCs) the $1,000,000 commercial general liability policy and $100,000 employee/worker bond.
Complete the Asbestos Open-Book Examination. Submit the completed asbestos open-book examination, included in the bond and fee letter.
Pay the initial license fee and receive your pocket card. Pay $200 (sole owner) or $350 (non-sole owner). CSLB issues the C-36 license number, wall certificate, and pocket card.

Preparation Resources

These materials are drawn from the regulator's own citations and the references applicants commonly use to prepare. CLR receives no compensation for listing them.

California Plumbing Code (CPC), current adopted edition — California Building Standards Commission (CCR Title 24, Part 5). Primary technical reference for the C-36 trade examination. Adopted from the Uniform Plumbing Code with California amendments.
C-36 Plumbing Study Guide (free PDF) — CSLB. Lists exam topic areas and weighting. Downloadable directly from cslb.ca.gov.
Plumber's Handbook (Howard Massey) — Craftsman Book Company. Widely used by C-36 candidates for venting calculations, fixture-unit sizing, and gas piping problems.
Contractors License Law & Reference Book (current edition) — LexisNexis Matthew Bender. Primary reference for the Law and Business portion of the CSLB examination.

Before Filing: A Checklist

Before submitting to CSLB, the applicant should have each of the following ready:

☐ Completed Application for Original Contractor License (Form 13A-1) — C-36 classification
☐ Certification of Work Experience (Form 13A-11) documenting four years of journeyman plumbing work
☐ $25,000 contractor license surety bond filed on the CSLB-prescribed form
☐ Workers' Compensation Certificate of Insurance — or signed Exemption Certification
☐ Completed Asbestos Open-Book Examination booklet

Common Application Pitfalls

The errors below are the ones that most frequently cost California Plumber applicants time, drawn from the cited board guidance.

Vague experience verification

A common reason CSLB returns the Certification of Work Experience is generic phrasing such as "helped out on jobsites" or "assisted the foreman". The verifier must use specific journeyman-level trade terminology, and the dates must match the applicant's W-2 record.

Bond and license number mismatch

The business name and license number on the contractor's bond must correspond exactly to the CSLB record. Even a missing "Inc." or a transposed digit will cause CSLB to reject the bond and delay issuance until a corrected rider is filed by the surety.

Missing the asbestos open-book exam

Many applicants assume the bond and fee letter only requires the bond and the initial fee. The completed Asbestos Open-Book Examination is required in the same envelope. Forgetting it sends the application back to the bottom of the Issuance Unit queue.

Workers' compensation exemption errors

Sole owners with no employees may file an exemption, but certain classifications (notably C-39 Roofing) cannot. Filing an exemption when not eligible voids the entire issuance package.

Letting the application time out

Once CSLB accepts the application, the applicant has 18 months to pass both examinations and submit all post-exam documentation. Applicants who pause to re-take the exam multiple times frequently let the clock expire and have to refile from scratch (forfeiting the $450 application fee).

Other California Trade Licenses

For a different California credential, see these companion guides published by CLR:

Answers to Common Questions

What does the C-36 plumbing license allow?

A C-36 contractor may install, maintain, and repair water supply systems, drain/waste/vent systems, gas piping, water heaters, and on-site waste disposal systems in residential, commercial, and industrial buildings. The classification is established under California Code of Regulations Title 16, Division 8, Article 3.

How is the C-36 trade exam structured?

The C-36 Plumbing trade examination is divided into five major sections: Planning and Estimating (~22%), Underground and Rough Systems (~22%), Finish Plumbing Installations (~20%), Gas Piping and Water Heating, and Service and Maintenance. Each portion is multiple-choice and closed-book.

What is the minimum bond required for a C-36 plumber?

A $25,000 contractor license bond is required, the same statewide CSLB amount in effect since January 1, 2023 under SB 607 and Cal. B&P Code §7071.6.

How long does the C-36 license remain valid?

CSLB licenses are issued for a two-year period and renew on a two-year cycle. Active sole-owner renewal is currently $450; non-sole-owner renewal is $700.

Does California accept NASCLA for the C-36 classification?

No. California does not accept the NASCLA Accredited Examination for any specialty (C-class) classification including C-36 Plumbing.

Primary Sources

Regulatory requirements on this page are drawn from the official board, statute, and exam-provider materials listed below.

Verified 2026-06-09 · Next scheduled review 2026-09-07