How to Verify a Plumber's License in All 50 States
Verifying a plumber's license before hiring is the single highest-leverage consumer-protection step available — and it takes less than five minutes. Yet most homeowners skip it, partly because licensing rules vary wildly by state. This guide explains what to check, where to check it in each state, and what an 'active' license actually guarantees (and doesn't).
Why state licensing matters
State plumbing licensing exists to verify that the person doing your work has documented training (typically 4-5 years of apprenticeship plus exam) and carries minimum liability insurance and a surety bond. Hiring an unlicensed plumber means your homeowner's insurance may not cover damage caused by their work, your local jurisdiction may not pass inspection (a problem if you sell), and you have limited recourse if the work fails.
Strong-licensing states
California, Florida, Hawaii, Louisiana, Massachusetts, Michigan, Minnesota, New Jersey, North Carolina, Oregon, South Carolina, Texas, Utah, Virginia, and Washington maintain robust statewide licensing with online lookup databases. In these states, every plumber working on residential property must hold an active state license. Look up via the state's contractor licensing board or department of labor website.
Local-licensing states (no statewide system)
Pennsylvania, New York, Indiana, and a handful of others handle plumbing licensing primarily at the city or county level. There is no single statewide database. To verify, contact the licensing office of the specific city or county where the work will be performed. In these states, beware of plumbers who say 'I'm not licensed because the state doesn't require it' — they almost certainly need a local license.
How to look up a license online
The general pattern: search '[state name] plumbing contractor license lookup.' The state's official site is usually in the top results, often a .gov domain. Enter the business name or license number. The lookup returns: current status (active/expired/revoked), license type and class, date issued, expiration date, and any disciplinary actions. If the license is expired or shows disciplinary action, that's a hard no.
What 'active' actually means
An active license means the holder passed the licensing exam, met the continuing education requirements, paid the annual fee, and maintains current liability insurance and surety bond on file. It does NOT mean the state vouches for the quality of the plumber's work, customer service, or pricing. License verification is a floor, not a ceiling. Cross-reference with Better Business Bureau, Google reviews, and word-of-mouth before hiring.
What to do if a plumber refuses to show ID
Any plumber who refuses to share their license number, refuses to let you photograph their license card, or claims their boss has it should not work on your home. Legitimate plumbers carry their card or have the number memorized and are happy to be verified. A refusal to share documentation is the single most reliable red flag of an unlicensed or actively-suspended operator.
Insurance and bond verification
Beyond the license, ask for the certificate of insurance (COI) showing current general liability coverage of at least $300,000 (most states require $500,000 or more). Ask for proof of the surety bond. A licensed plumber can produce both within a day; an unlicensed one will stall. If the work involves a significant water service or sewer line, also confirm workers compensation coverage — a worker injured on your property without workers comp can sue you personally.
License verification is the cheapest insurance available in home repair. Five minutes on your state's licensing website before signing any contract protects you from the worst categories of plumbing fraud and gives you legal standing if work goes wrong. Make it a habit on every job over $500.