How to Hire a Plumber: License, Questions, and Red Flags

Hiring a plumber safely means verifying their state license, confirming they carry general liability insurance and workers compensation, and getting at least three written quotes for any job over $500. Skipping any of these steps is how homeowners end up with unlicensed work, failed inspections, and no recourse when something goes wrong. The steps below give you a repeatable process from first call to signed contract.

What Type of Plumber Does Your Job Require?

Not every plumbing job requires the same level of plumber. Before calling around, identify which category your job falls into, since this determines the license tier you need and affects the rates you should expect.

Service and repair plumbers handle most routine residential calls: clogged drains, leaking faucets, running toilets, and similar problems. These jobs typically do not require a permit and can be completed by a journeyman plumber.

Replacement and installation plumbers handle water heater replacements, garbage disposal installs, and fixture replacements. These jobs may or may not require a permit depending on your jurisdiction.

Pipe and system plumbers handle new construction, repiping, sewer line work, and gas line additions. These jobs almost always require a permit and inspection, and typically require a master plumber to pull the permit.

Knowing your category before calling gives you a cleaner conversation when asking about license level and permit responsibility.

How to Verify a Plumber's License in Your State

Every state that licenses plumbers maintains a public lookup tool through the state contractor licensing board or the department of consumer affairs. Before hiring, look up the plumber's license number on the state board's website and confirm that the license is active, not expired or suspended.

What to check in the state lookup:

• License status: active and current
• License type and classification (residential, commercial, master, journeyman)
• Expiration date
• Any disciplinary actions or complaints on record

Do not accept a photo of a license card as verification. License cards can be outdated, altered, or borrowed. The state database is the authoritative source. For a step-by-step verification walkthrough that applies to all trades, see How to Vet a Contractor's License and Insurance.

What Insurance Should a Plumber Carry?

A licensed plumber working on your property should carry two types of insurance: general liability and workers compensation.

General liability insurance covers property damage the plumber causes - a burst pipe, a flooded floor, a broken tile. Minimum coverage of $500,000 is a reasonable baseline for residential work; $1,000,000 is common and preferred. Ask for a certificate of insurance (COI) naming your address and confirm the policy is current before any work begins.

Workers compensation insurance covers medical costs if a plumber or their helper is injured on your property. Without workers comp, an injured worker can make a claim against your homeowner's insurance policy, and some policies will not cover it. Any plumber with employees must carry workers comp under most state laws. Sole proprietors working alone may be exempt, but you should confirm this with your insurance agent.

How Many Plumbing Quotes Should You Get?

For any plumbing job over $500, get a minimum of three written quotes. Quotes for small repairs - under $200 - can reasonably go to one or two plumbers because the overhead of coordinating multiple visits may not be worth the price difference. The following table gives practical guidance:

Each quote should specify labor rate, estimated hours or flat fee, parts and materials, trip fee, and permit cost if applicable. Comparing quotes on price alone is a mistake if the scopes differ - make sure each quote covers the same work before comparing numbers. For guidance on reading and comparing contractor quotes, see How to Get Accurate Contractor Quotes.

Questions to Ask a Plumber Before Hiring

Before confirming a plumber for any job, ask these questions and document the answers:

1. Are you licensed in this state, and what is your license number?
2. Do you carry general liability and workers compensation insurance?
3. Will you pull the permit if this job requires one, and is that included in your quote?
4. Is this a flat-rate or hourly quote, and what conditions would change the final price?
5. What is your payment schedule - deposit now, balance on completion?
6. What is your workmanship warranty on this job?

Any plumber who refuses to answer questions about license number, insurance, or permit responsibility should not be hired. Legitimate plumbers answer these questions routinely without hesitation.

Red Flags When Hiring a Plumber

The Federal Trade Commission identifies high-pressure tactics, demands for upfront cash, and reluctance to provide written documentation as common markers in home improvement fraud. Plumbing is among the trades where these patterns appear regularly.

Watch for:

• No written quote or refusal to put the price in writing
• Demand for full payment in cash before work begins
• Unable or unwilling to provide a license number
• Claims their work does not need a permit when your building department says it does
• Unusually low bid that is far below other quotes (often signals unlicensed or underinsured work)
• Pressure to decide immediately without time to get competing quotes

If you encounter these signs, stop the conversation and call another plumber. For a broader overview of home improvement fraud patterns, see How to Avoid Home Improvement Scams.

What a Plumbing Contract Should Include

Before work begins on any job over $500, get a written contract that specifies:

• The exact work to be performed (scope, location, method)
• Parts and materials: brand, model, and specifications for major items
• Labor pricing: hourly rate and estimated hours, or a firm flat fee
• Trip fee and whether it applies to the total
• Permit responsibility and whether permit fees are included
• Payment schedule: deposit amount, timing of final payment
• Workmanship warranty: what it covers and for how long
• What happens if hidden conditions (corroded pipes, damaged structure) are discovered

A contract protects both parties. A plumber who resists putting terms in writing is telling you something important about how they operate. Review the contract carefully before signing. For a guide to the clauses that matter most in any home improvement contract, see How to Read a Contractor Contract.

For specific cost expectations before your first call, see Plumber Cost Per Hour: What Homeowners Pay in 2026. Understanding typical rates before you call gives you a useful reference point when evaluating whether a quote is reasonable.