Plumber license requirements in Arizona.
Arizona licenses plumbing contractors at the state level through the Registrar of Contractors. Plumbing is split by the kind of work you do — commercial, residential, or both — and every licensed contractor has to carry a surety bond that scales with the license class and expected volume.
What Arizona requires.
C-37 — Plumbing (commercial)
Commercial plumbing contracting.
R-37 — Plumbing (residential)
Residential plumbing contracting.
CR-37 — Plumbing (dual)
Covers both commercial and residential plumbing work.
Getting the C-37 — Plumbing
- Be at least 18 and provide documentation of citizenship or legal resident status
- Document at least four years of experience working under a licensed plumber — up to two of those years can come from accredited technical training
- Pass the Arizona Statutes and Rules exam plus the applicable plumbing trade exam
- Pass a criminal background check
- File a surety bond sized to your license classification and anticipated gross volume
- · Bond amounts scale: residential licenses commonly run $4,250 under $375,000 in gross volume and $7,500 above it, while commercial bonds can reach $50,000. Confirm your figure with the ROC.
Verified 2026-08 against the sources below. Licensing rules change — confirm with the board before relying on this page.
Arizona plumbing licensing FAQ.
Do you need a license to do plumbing work in Arizona?
Yes. Arizona requires a plumbing contractor license from the Registrar of Contractors. Which one depends on your work: C-37 for commercial, R-37 for residential, or CR-37 to cover both.
What is the difference between C-37, R-37, and CR-37 in Arizona?
They are the Registrar of Contractors’ plumbing classifications. C-37 covers commercial plumbing, R-37 covers residential, and CR-37 is the dual license covering both.
How much experience do you need for an Arizona plumbing license?
Four years of experience working under a licensed plumber. Up to two of those years can be satisfied with accredited technical training, so schooling can cut the on-the-job requirement in half at most.
Do Arizona plumbing contractors need a bond?
Yes. Every licensed Arizona contractor must file a surety bond, and the amount scales with your classification and anticipated gross volume — residential bonds commonly run $4,250 or $7,500, and commercial bonds can reach $50,000.
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