The tools
Where to look them up.
| Tool | Use it to |
|---|---|
| BIS License Search (DOB) | Confirm the status of a license, registration or certification |
| DCWP license lookup | Confirm a Home Improvement Contractor license, required for work on residences such as basements, driveways, fences, patios and pools |
| Know Your Construction Professional directory | Research a professional’s record; it covers 1998 to the present |
| DOB disciplinary action look-ups | Check discipline for master electricians, master plumbers, other licensees, professional engineers and registered architects, and filing representatives |
Before you sign
A quick checklist.
Get the license number
Ask for the name, license number(s) and a New York City company address up front.
Look it up
Search the license in DOB’s license search and, for residential work, the DCWP lookup.
Check discipline
Use DOB’s disciplinary look-up pages to see whether the licensee has actions or voluntary surrenders.
Put it in writing
DOB recommends a written contract that includes the tradesperson or company name, a New York City address and license number(s).
Plumbing and gas work in particular must be done by a Licensed Master Plumber, and permit applications generally go through a Professional Engineer or Registered Architect.
Hired someone and now have a violation or failed inspection? Call us and we’ll review the record.
Call (929) 367-0962Questions
Frequently asked.
Does a general contractor need a license in NYC?
It depends on the work. Residential home improvement contractors need a DCWP Home Improvement Contractor license, and specific trades like plumbing and electrical have their own DOB licenses.
Where do I find disciplinary history?
DOB has separate look-up pages for master electricians, master plumbers, other licensees, and engineers and architects.
What if the work was done by an unlicensed person?
Work may need to be inspected, corrected or re-done by a licensed professional, and any resulting violation has to be resolved. A review of the property’s record is the best first step.
Sources
Official sources.
General information about New York City procedures, last reviewed November 2026. Amounts and rules change and every property is different, so this isn’t legal advice. Call us about your specific situation.