License check
How to check an irrigation contractor's license in Suffolk or Nassau
A license number takes a minute to check and tells you the company can legally do the work. Here is who issues it in each county, where to look it up, and what else to ask, from the official pages we read on 2026-11-03.
What New York State and federal rules say
- New York's Sanitary Code requires everyone who tests backflow prevention assemblies to be certified under 10 NYCRR section 5-1.31.
- The state Department of Health stopped issuing initial backflow tester certifications on March 1, 2011, after Public Health Law changes removed its duty to issue them.
- A backflow tester's certificate of course completion comes from the training provider, once the applicant satisfactorily completes the course.
In Suffolk County
- On Suffolk's restricted license application, Irrigation appears as a category under the Restricted Electrical heading.
- Suffolk requires a separate application for each restricted license and for each category on it.
- Backflow Tester is one of the license types listed by Suffolk Consumer Affairs.
- 1Step 1Choose Backflow Tester in Suffolk's License and Complaint Violation Look Up to check a backflow tester's county license.
- 2Step 2To find an irrigation contractor's restricted license, pick Restricted Electrical License in Suffolk's License and Complaint Violation Look Up.
- 3Step 3The state Department of Health's cross-connection control page links a List of New York State Certified Backflow Testers.
- 4Step 4Suffolk Consumer Affairs, reachable at (631) 853-4600, also verifies backflow tester and restricted licenses by phone.
In Nassau County
- Consumer Affairs in Nassau includes lawn irrigation contractors on its list of who must be licensed.
- Among the work categories on Nassau's license application is one for irrigation and sprinklers.
- Home improvement contractors doing sprinkler or irrigation work in Nassau must submit a New York backflow tester certification from a course provider approved by the state Department of Health.
- 1Step 1An irrigation contractor's Nassau license, issued as a home improvement license, can be searched in the Valid Business License Search.
- 2Step 2In Nassau, where irrigation contractors must submit a backflow tester certification, the state's cross-connection control page links the list of certified testers.
Towns with a license of their own
- Town of Huntington: Under Chapter 153 of its code, Huntington issues limited plumbing licenses for specified services, and irrigation systems are one of them.
- Town of Shelter Island: Shelter Island's notice to contractors says every contractor or subcontractor working on the island, landscapers included, needs a town license.
Beyond the license
- Ask for a certificate of insurance sent to you by the insurer, naming you as the certificate holder.
- Ask who files the permit and books the inspections, and get it in the contract.
- Get the price, the scope, the start and finish dates and the payment schedule in a written contract.
Related
Questions homeowners ask
Does a sprinkler system need a backflow preventer?
Water suppliers generally require one on irrigation systems, tested by a certified tester. Ask your water supplier what it requires.
Do irrigation contractors need a license on Long Island?
Rules vary by county and town. The town pages list what each official page says.
Sources
Every fact on this page comes from these official pages. Rules and fees change, so confirm with the office before you file anything.
- NYS Department of Health, backflow tester certification instructions and procedures (read 2026-11-03)
- NYS Department of Health, Cross-Connection Control (read 2026-11-03)
- Suffolk County Consumer Affairs, Restricted License Application (CA-L11) (read 2026-11-03; page dated 3/26)
- Suffolk County Consumer Affairs, Licensing and Enforcement (read 2026-11-03)
- Suffolk County, License and Complaint Violation Look Up (read 2026-11-03)
- Nassau County Consumer Affairs, Who Must Be Licensed? (read 2026-11-03)
- Nassau County Consumer Affairs, Home Improvement Business License Application (PDF) (read 2026-11-03)
- Nassau County Consumer Affairs, Valid Business License Search (read 2026-11-03)
- Town of Huntington, Town Code Chapter 153, Plumbing (PDF) (read 2026-11-03)
- Town of Shelter Island, Notice to All Contractors (read 2026-11-03)
Checked 2026-11-03. Facts come only from the official pages listed, read on that date.
Talk the job through before you call anyone
Tell us about the house and the job in about four minutes. Revival calls you, free, to go over the scope, the budget, the timing and your town's permit office. Contractor matches open as our first licensed partners sign.