15 Questions to Ask a Plumber Before You Hire
Before hiring a plumber, confirm they’re actively licensed in your state, carry liability insurance and workers’ comp, provide an upfront written flat-rate quote, warranty both labor and parts for at least one year, and clarify who actually performs the work. These questions expose unlicensed operators, hidden fees, and low-quality workmanship — print this list and bring it to every estimate.
Why Asking Questions Matters
Plumbing work is hidden inside walls, under floors, and behind fixtures — you often can’t see whether it was done well until something fails. The right questions before you hire reveal whether a plumber is qualified, fairly priced, and accountable. The NAPHCC (Plumbing-Heating-Cooling Contractors Association) recommends homeowners always verify credentials and get written documentation before any work begins.
With the national median plumber wage at $34.70/hr per the Bureau of Labor Statistics (May 2025) — and retail rates to homeowners running $75–$200/hr — there’s real money at stake. A $3,000 repiping job done poorly costs $6,000+ to redo.
Licensing & Insurance Questions
1. Are you licensed in this state, and what’s your license number?
Why it matters: Licensing ensures the plumber passed trade exams and meets your state’s standards. Unlicensed work often violates code, voids insurance claims, and creates problems at resale.
| Good Answer | Bad Answer |
|---|---|
| ”Yes — license #PLB-12345, you can verify it on [state board site]." | "I’ve been doing this 20 years, I don’t need a license.” |
Use our state-by-state contractor license verification guide to confirm any number they provide.
2. Whose license covers the permit for this job?
Why it matters: In states with tiered licensing, a journeyman plumber may do the physical work, but only a master plumber can pull permits and take legal responsibility. If the company sends a worker operating under a license that isn’t actively supervised, your permit may be invalid.
| Good Answer | Bad Answer |
|---|---|
| ”Our master plumber [name] pulls all permits — his license covers our crew." | "We don’t usually bother with permits for this type of job.” |
3. Do you carry liability insurance and workers’ comp?
Why it matters: Without general liability, you pay if they damage your property. Without workers’ comp, you may be liable for their employee’s injury on your property.
| Good Answer | Bad Answer |
|---|---|
| ”Yes — I can email you our Certificate of Insurance today." | "Insurance just drives up the price. We’re careful.” |
4. Who will actually do the work — and what’s their qualification?
Why it matters: Some companies send apprentices for jobs that warrant a journeyman or master. You’re paying for expertise — know who shows up.
| Good Answer | Bad Answer |
|---|---|
| ”Our journeyman [name] handles these — he’s been with us 8 years." | "Whoever’s available that day.” |
Pricing Questions
5. Is your pricing flat-rate or hourly?
Why it matters: Flat-rate protects you from slow work or unexpected complications inflating the bill. Hourly only makes sense for genuinely open-ended diagnostic work.
| Good Answer | Bad Answer |
|---|---|
| ”Flat-rate — I’ll quote you the total before I start." | "Hourly. I won’t know how long it takes until I get in there.” |
6. Can I get the full quote in writing before work starts?
Why it matters: Verbal quotes are unenforceable. A written quote protects both parties and lets you compare contractor bids fairly. Learn how to read a contractor quote so you know what each line means.
| Good Answer | Bad Answer |
|---|---|
| ”Absolutely — I’ll email it within the hour." | "I’ll just write it on the invoice after.” |
7. Is there a service/trip fee, and is it credited toward the repair?
Why it matters: Service fees ($50–$200) are standard and cover the truck roll. The key question is whether that fee gets applied to the repair cost if you proceed.
| Good Answer | Bad Answer |
|---|---|
| ”$89 trip fee, fully credited if you go ahead with the work.” | Doesn’t mention the fee until the invoice arrives. |
8. What could change the final price? (The Change-Order Question)
Why it matters: Plumbing hides surprises — corroded pipes behind drywall, tree roots in the sewer line, outdated fittings that don’t match. You need to know how additional costs get communicated and approved before the plumber proceeds.
| Good Answer | Bad Answer |
|---|---|
| ”If I find more damage behind the wall, I’ll stop, show you, and give you a revised written quote before continuing." | "We just add it to the bill — you’ll see it at the end.” |
This is the single most important question for jobs involving wall access, drain repair, or anything where hidden conditions are likely.
9. Do you charge extra for emergencies or after-hours?
Why it matters: After-hours rates run 50–100% higher than standard rates. Know this before you call at midnight. See emergency plumber cost for benchmarks.
| Good Answer | Bad Answer |
|---|---|
| ”After-hours is time-and-a-half on the labor rate — I’ll quote it before starting." | "Whatever it takes” (vague, no cap). |
Warranties & Permits
10. Do you warranty your labor — and for how long?
Why it matters: Parts have manufacturer warranties, but if the installation fails, you need a labor warranty to cover the re-repair at no charge.
| Good Answer | Bad Answer |
|---|---|
| ”1-year labor warranty on all work, 2 years on major installs, in writing." | "If something goes wrong, just call me.” (No documentation.) |
11. Does the warranty cover parts AND labor?
Why it matters: A “warranty” that only covers the $15 part but not the $400 in labor to re-access a wall and redo the repair is nearly worthless.
| Good Answer | Bad Answer |
|---|---|
| ”Full coverage — parts and labor — for 12 months." | "The part’s under manufacturer warranty; labor is separate.” |
12. Will you pull all required permits and schedule inspections?
Why it matters: Bigger jobs (water heaters, repiping, sewer-line replacement, gas lines) require permits and inspection. Unpermitted work creates code violations that surface at resale, insurance claims, or future failures.
| Good Answer | Bad Answer |
|---|---|
| ”Yes — permit fee is included in the quote, and I schedule the inspection." | "Permits just slow things down and cost you more.” |
Logistics & Accountability
13. When can you start, how long will it take, and what’s the payment schedule?
Why it matters: Clear timelines prevent a job from dragging on. Payment schedules should align with work completion — never 100% upfront. See how much deposit is normal.
| Good Answer | Bad Answer |
|---|---|
| ”Start Monday, done by Wednesday. 50% at start, 50% on completion." | "Depends on my other jobs. I’ll need full payment to order parts.” |
14. What happens if you find additional damage behind the wall?
Why it matters: This is the change-order question applied to a specific plumbing scenario. Behind-the-wall surprises are the #1 source of billing disputes in plumbing. You want a commitment to stop-and-communicate, not bill-and-surprise.
| Good Answer | Bad Answer |
|---|---|
| ”I stop work, take photos, explain options, and get your written approval for any price change." | "I’ll just fix whatever I find — you want it done right, don’t you?“ |
15. Can you provide references or recent review links?
Why it matters: Cross-check with Google, Yelp, and the BBB. A plumber confident in their work will happily point you to satisfied customers. See how to find a good plumber near you for the full vetting checklist.
| Good Answer | Bad Answer |
|---|---|
| ”Sure — here are three recent customers and my Google profile." | "I don’t really do reviews.” |
Red Flags in Their Answers
Watch for these patterns across multiple answers:
- Refuses to put anything in writing — pricing, warranty, timeline, scope.
- Demands large upfront cash — more than 30–50% deposit on a major job is a red flag.
- Can’t name their license number or gets evasive about insurance documentation.
- Pressures you to decide immediately — “this price is only good today” is a high-pressure sales tactic.
- Recommends expensive work without diagnostics — e.g., “your whole house needs repiping” without performing a camera inspection first.
- Won’t clarify who does the work — you may get an unsupervised apprentice.
The EPA’s WaterSense program also certifies certain plumbing professionals in water-efficient installations — this is a bonus credential worth asking about for fixture upgrades or bathroom remodels.
Frequently Asked Questions
What should I ask a plumber before hiring? Confirm licensing and insurance, get an upfront written quote, ask about the fee structure, warranty (parts AND labor), permits, change-order policy, timeline, and who performs the work. The NAPHCC recommends written documentation for all terms.
How do I avoid being overcharged by a plumber? Get flat-rate written quotes from 2–3 plumbers, know the BLS median wage ($34.70/hr per BLS data) as your benchmark, and watch for high-pressure upsells — especially repiping recommendations without camera evidence.
Should I get plumbing quotes in writing? Always. A written, flat-rate quote protects you legally and makes comparing contractor bids straightforward. Verbal quotes are unenforceable and lead to billing disputes.
Do plumbers charge just to come out? Usually yes — a $50–$200 service/trip fee is standard. Reputable companies credit this toward the repair if you proceed. Ask about this before scheduling.
What’s the most important question to ask a plumber? The change-order question: “What happens if you find additional damage behind the wall, and how will you communicate cost changes before proceeding?” This one question prevents the most common billing dispute in residential plumbing.
Last updated: June 2026. Wage data: Bureau of Labor Statistics, Occupational Employment & Wage Statistics, May 2025. Trade standards: NAPHCC. For informational purposes only — verify credentials and get local quotes.