How to Verify a Contractor License in Any State or Province (Official Lookups)

Hiring a contractor, plumber, electrician or HVAC company? Checking their license takes a couple of minutes and is the best way to avoid unlicensed work. Lookup searches are among the most common licensing searches online, but each state and province runs its own database with its own layout. This guide shows you where to look and what to check.

The five checks that matter

1. Get the exact business name and license number from the contractor.
2. Search the official database for the state or province where the work happens. Your contractor's home state doesn't count if the job is somewhere else.
3. Confirm the status is active and note the expiration date.
4. Match the license type to the work. An electrical license doesn't cover plumbing, and a contractor license is different from an individual worker's card.
5. Check local rules. Some cities and counties license trades separately. The verified local-licensing facts on our requirement pages flag where the state says this applies.

Lookups we host (official open data)

For these jurisdictions we load the official public data file into a fast search. Records show name, license number, class, status and city only.

Note: the New York file is the Department of Labor's public-work contractor registry, which is not a trade license. For New York City trade licenses, use the NYC Department of Buildings.

Everywhere else: go to the board

For other states we link the licensing board's website. Most boards have a search box on their homepage or under Verify a license.

These board links come from our directory of licensing authorities. If a link has moved, search the board's name on the state's official .gov site.

Where local licensing applies (verified)

• Arizona (hvac): Phoenix: plumbing and mechanical work needing a permit must be done by a licensed Journeyman or Apprentice. (City-level rule (Phoenix, AZ)) — source: Journeyman and Apprentice Licensing | City of Phoenix, verified 2026-10-18
• Arizona (plumber): Phoenix: plumbing and mechanical work needing a permit must be done by a licensed Journeyman or Apprentice. (City-level rule (Phoenix, AZ)) — source: Journeyman and Apprentice Licensing | City of Phoenix, verified 2026-10-18
• Colorado (general contractor): Unincorporated Jefferson County: general, roofing and mechanical contractors need a county contractor license. (County-level rule (Jefferson County, CO)) — source: Contractor Licensing | Jefferson County, CO, verified 2026-10-18
• Illinois (electrician): A Chicago electrical contractor must be owned by or employ at least one supervising electrician. (City-level rule (Chicago, IL)) — source: chi_supervising_electrician.pdf, verified 2026-10-18
• Illinois (general contractor): A Chicago general contractor license is required for most building construction, alteration, repair and demolition in the city. (City-level rule (Chicago, IL)) — source: chi_general_contractor.pdf, verified 2026-10-18
• Illinois (plumber): Chicago requires a City plumbing contractor license even for State-licensed plumbing contractors. (City-level rule (Chicago, IL)) — source: chi_plumbing_contractor.pdf, verified 2026-10-18
• Illinois (plumber): Chicago plumbing contractor licenses are issued by the Board of Plumbing Examiners. (City-level rule (Chicago, IL)) — source: chi_plumbing_contractor.pdf, verified 2026-10-18
• Michigan (electrician): The City of Detroit issues its own electrical licenses and registrations. (City-level rule (Detroit, MI)) — source: mi_bcc_electrical.pdf, verified 2026-10-18
• New York (electrician): City of Troy: about six years of experience, $100 exam (75% to pass), $200 license fee, 6 hours of continuing education to renew. (City-level rule (Troy, NY)) — source: Electrician Licenses | Troy, NY, verified 2026-10-18
• New York (general contractor): NYC Home Improvement Contractor license (DCWP): license application fee includes two Home Improvement Exam attempts; $50 per retake after that. (City-level rule (NYC)) — source: Home Improvement Contractor License, verified 2026-10-18
• Pennsylvania (general contractor): Some of Pennsylvania’s 2,562 municipalities set local licensing for contractors and trades. (State-level rule) — source: Contractor Licensing | Department of Labor and Industry | Commonwealth of Pennsylvania, verified 2026-10-18

Red flags

• The contractor can't or won't give you a license number.
• The name on the license doesn't match the business on the contract.
• The license status isn't active, or the classification doesn't match the job.

How to use this guide

• Every fact above links to the official page it came from, with the date we checked it. Rules change — confirm with the board before you apply or pay.
• To check whether a specific person or company holds a license, use our license lookup (TX, CA, WA, OR, NY and Québec RBQ data) or the board's own search.
• Moving between states or provinces? See the electrician reciprocity matrix and our Red Seal guide.

FAQ

Who licenses contractors in Arizona?

Arizona Registrar of Contractors licensing: 877.692.9762. (Contractor license (AZ ROC, B / B-1 / B-2 / KB)) — source: Applying for a License | Arizona Registrar of Contractors, verified 2026-10-18

Who licenses contractors in California?

California CSLB contractor license (e.g. "B" General Building) required for contract work valued at $1,000 or more (labor + materials), or work needing a building permit or using employees. (Contractor license (B General Building, CSLB)) — source: What Kind of Contractor Do You Need? - CSLB, verified 2026-10-18

Who licenses contractors in Oregon?

Construction Contractors Board licensing call center: 503-378-4621. (Contractor license) — source: Oregon Construction Contractors Board : Licensing : State of Oregon, verified 2026-10-18