Plumbing Contractor License in California: Requirements, Qualifier, Bond and Exams

Yes — statewide.

Anyone contracting for construction work of $1,000 or more in labor and materials, or for any job needing a building permit, must hold a CSLB license in the proper classification, and for plumbing contracting that classification is C-36 (Bus. & Prof. Code §7048, amended by AB 2622 effective January 1, 2025).

The rule is written around the business, not the plumber: California's contractor law does not apply to a person who does the work as an employee paid wages as their sole compensation and who does not customarily engage in an independently established business (§7053).

The state credential therefore sits with the contracting business, and individual plumbers work under it.

The Contractors State License Board (CSLB) issues the license.

The CSLB classification for plumbing contracting is C-36 Plumbing Contractor.

CSLB defines its scope as providing a means for a supply of safe water, ample in volume and of suitable temperature for the purpose intended, and the proper disposal of fluid waste from the premises in all structures and fixed works.

A plumbing contracting business holds its CSLB license in this classification, and the qualifier named on it carries the experience and exams covered next.

Every CSLB license needs a qualifier.

That person must be at least 18 and have at least four years of journey-level experience — as a journeyperson, foreperson, supervising employee or contractor — within the last 10 years, in the classification being applied for.

The qualifier can be a Responsible Managing Officer (RMO) or a Responsible Managing Employee (RME); an RME must be a bona fide employee working at least 32 hours a week or 80% of business hours, and may not be the qualifier on any other active CSLB license.

One qualifier may act for an additional firm only with at least 20% common ownership (or a subsidiary or joint venture, or the same majority officers), and never for more than three firms in any one-year period.

The qualifier must pass two computer-based exams: the law and business exam plus the trade exam, administered by PSI Exams, unless waived.

Before CSLB issues the license, every applicant must also be fingerprinted and complete an open-book asbestos exam.

Our research does not carry the exams' content outlines, so confirm the exam content with CSLB and PSI rather than relying on secondhand summaries.

Every CSLB license requires a $25,000 contractor's bond (Bus. & Prof. Code §7071.6).

A separate $25,000 qualifying individual's bond is also required when the qualifier is neither the proprietor nor a general partner — for example an RME, or an RMO who is not an owner (§7071.9).

Ask CSLB or your bonding agent how that bond applies to your ownership structure before you apply.

Our research established these bond amounts; it did not establish a general liability insurance figure for California plumbing contractors, so confirm insurance with CSLB before you bid.

CSLB's 2026 fee schedule lists $450 for the original application (exam or waiver, one classification), $200 for the initial license for a sole owner or $350 for a non-sole owner, and $230 to replace a qualifier.

The license is initially issued for a two-year period, and active licenses renew every 2 years: $450 for a sole owner, $700 for a non-sole owner (inactive licenses renew every four years).

On continuing education, the CSLB sources we read set no general CE requirement for renewal, but our research could not confirm that, so ask CSLB before you plan the renewal year.

With three states.

CSLB lists reciprocity agreements with Arizona, Louisiana and Nevada under which the trade exam may be waived case by case; the law and business exam is still required.

The list comes from CSLB's licensing guide, so confirm the current agreements with CSLB before you count on a waiver.

If the qualifier disassociates from the business, the licensee must notify CSLB within 90 days and has 90 days after the date of disassociation to replace them — otherwise the license is automatically suspended or the classification removed (Bus. & Prof. Code §7068.2).

Replacing a qualifier is a $230 line on CSLB's 2026 fee schedule.

Two rules narrow the pool of replacements: an RME may not be the qualifier on any other active CSLB license, and a qualifying individual may act for no more than three firms in any one-year period, so line up the replacement before the departure when you can.

Yes, and it is small.

A CSLB license is required for any construction job of $1,000 or more in labor and materials, or any job needing a building permit (Bus. & Prof. Code §7048, as amended by AB 2622, effective January 1, 2025).

Watch the date on the source: CSLB's older Get Licensed to Build guide still prints a $500 threshold, and that figure is out of date — the 2026 law book shows $1,000.

Section 7048's small-job exemption carries its own conditions that our research did not capture in full, so ask CSLB before relying on it for work under the threshold.