Westchester plumbing and home improvement licences, in plain terms
Updated October 30, 2026 · 3-minute read · Old House Sewer Lines
A Westchester County plumbing license is issued by the county Board of Plumbing Examiners, and county law says a master plumber's licence allows plumbing work anywhere in the county. Home improvement contractors need a different county licence. Yonkers has its own rules for contractors, so check with the city.
The Board of Plumbing Examiners sits inside the county Department of Consumer Protection at 148 Martine Avenue in White Plains (2026 exam application). Under the county Plumbing Licensing Law, no business may install, alter, replace, test or repair plumbing in the county when a plumbing permit is required unless it holds a valid plumbing licence. A licence from the board permits plumbing work "with no restrictions in any city, town or village in the county" (Plumbing Licensing Law). Unlawful plumbing work can cost up to $5,000 in civil penalties, with every day of violation treated as its own offense.
How the plumbing licence is earned
The 2026 county application sets the bar by experience. A master plumber applicant must document 10 years of full-time work for a licensed master plumber. A journey-level applicant needs five years as an apprentice or a completed five-year apprenticeship. Application fees are $50 for master and $25 for journey-level. The county tells consumers to ask plumbers to show their Westchester County licence card (Plumbers and Electricians).
Two point-of-sale sewer laws lean on the same licence. Rye and the Village of Mamaroneck accept a lateral certification only from a plumber licensed to do business in Westchester County, and the village's sample letter asks for the plumber's county licence number. The details are in Rye's sewer lateral law and the Village of Mamaroneck sewer certificate.
The home improvement licence
The New York Attorney General lists Westchester among the counties where home improvement contractors must be licensed (NY Attorney General). Here the Department of Consumer Protection issues that licence. Applicants undergo a criminal background check and must supply proof of insurance and financial responsibility, and the county can revoke a licence. Operating without one is a Class A misdemeanor, punishable by one year, a $5,000 fine or both (Choosing a Home Improvement Contractor).
Yonkers is the exception. The county says contractors who work in Yonkers must be licensed by the city's Consumer Protection Bureau. An archived 2015 copy of the Yonkers code also required a city certificate of competency for plumbing and exempted licensed plumbers working within their trade from the city home improvement licence. That copy is old, so ask Yonkers' Department of Housing and Buildings for the current rules before relying on it.
| Licence | Issued by | Notes |
|---|---|---|
| Master or journey-level plumber | Westchester County Board of Plumbing Examiners | Needed when a plumbing permit is required; valid countywide under county law |
| Home improvement contractor | Westchester County Department of Consumer Protection | Background check and proof of insurance |
| Yonkers contractor licence | City of Yonkers Consumer Protection Bureau | Required for contractors working in Yonkers |
| Local plumbing licences elsewhere | Not confirmed | Ask your city or village building department |
Whether Mount Vernon, New Rochelle or White Plains issue their own plumbing licences in addition to the county licence could not be confirmed. Ask the building department before work starts. No homeowner exemption for doing your own plumbing appears in the county law text. Yonkers and Mount Vernon residents can also check a contractor through their local consumer affairs office, the county says. For how licences fit into the rest of the hiring decision, see choosing a sewer contractor and the hiring and paying topic.
Key facts
- Plumbing licences come from the Westchester County Board of Plumbing Examiners, 148 Martine Avenue, White Plains (county application).
- Master plumber applicants need 10 years of full-time experience; journey-level applicants need five (county application).
- Unlawful plumbing work: up to $5,000 in civil penalties per day of violation (Plumbing Licensing Law).
- Unlicensed home improvement work is a Class A misdemeanor in Westchester (Westchester County).
- Contractors working in Yonkers need a Yonkers licence (Westchester County).