Eight questions to ask every plumber
Run this list with every contractor before you sign. Most legitimate pros will answer in under five minutes and appreciate that you're doing your homework — a pro who pushes back on these questions is telling you something important about how they do business.
- What is your state license number, and is it currently active?
- Do you carry general liability insurance? Can I see proof?
- Will you provide a written, line-itemed estimate before any work begins?
- Are permits required for this job, and will you pull them in your name?
- What is your warranty on labor and parts?
- Do you charge a flat rate or by the hour, and what is your dispatch fee?
- Will you protect flooring and clean up before leaving?
- How quickly can you start, and do you offer 24/7 emergency response?
Red flags to walk away from
If any of the following come up during a quote, stop the conversation and call a different plumber. The cost of restarting the process is almost always less than the cost of fixing a botched or unpermitted job after the fact.
- ⚠ No license number, or a license that does not appear in your state's contractor lookup.
- ⚠ A verbal estimate only — never sign a verbal quote on plumbing work.
- ⚠ "Cash only" pricing or large up-front deposits (more than 10–20%) before materials are ordered.
- ⚠ Pressure to skip permits on water heater, sewer, or gas line work.
- ⚠ Wildly low quote that comes in 30%+ below the next two — usually means unlicensed help or omitted scope.
The 60-second license check
Every U.S. state lets you verify a contractor license online for free — usually through the state's contractor licensing board, the secretary of state, or the department of labor. Search "[your state] contractor license lookup" and enter the license number the pro gave you. The lookup will show whether the license is active, what trades it covers, when it expires, and whether there are any open complaints or disciplinary actions. A fresh same-day check the morning of your appointment costs you nothing and catches recent suspensions.
Getting multiple quotes
Contact two or three local plumbers directly and compare written quotes before you sign anything. For pricing context, see our plumbing cost guide; for after-hours work, see our emergency plumbers guide.