Unpermitted plumbing has a favorite moment to surface: the buyer's inspection on the house you're trying to sell, where a water heater with no permit or a bathroom the county never saw becomes a closing-table negotiation you lose. Plumbing is a licensed trade almost everywhere - which means the vetting system already exists, and most homeowners simply never use it.
This playbook shows you how: what the license tiers actually authorize, how to run your state's lookup in five minutes, which jobs legally require permits and who should pull them, the insurance paperwork that protects your house, and the eight questions that sort professionals from pretenders before anyone touches a pipe.
The Sale-Day Surprise: What Unpermitted Work Costs Later
Skipped permits feel free right up until the appraisal, the insurance claim, or the buyer's inspector. Then the options are retroactive permitting - opening walls to show the inspector what's inside them - renegotiating the sale price, or watching a deal die. Water damage traced to unlicensed work also gives insurers their favorite word: denied. The cheap unlicensed job is routinely the most expensive plumbing decision a homeowner makes.
License Tiers Decoded: Apprentice, Journeyman, Master
What each tier may do unsupervised
An apprentice works under supervision - never alone on your job. A journeyman has passed a trade exam and works independently on most repairs and installs. A master plumber carries the highest license, can design systems, pull permits, and run a company. Titles vary slightly by state, but the ladder is near-universal.
Whose license is on your permit
Permits are pulled under a master's license (or the company's contractor license held by one). Ask whose number goes on yours - the answer connects an accountable, board-disciplinable human to your job. Vague answers here predict vague accountability later.
Contractor license vs plumbing license
A general contractor license is a business credential; it does not authorize plumbing. Remodels are where this bites: the GC is licensed, the actual pipe work is done by whoever was cheap that week. For plumbing scope, the plumbing license is the one that counts.
Run the Lookup: Verifying a License in Five Minutes
Every licensing state runs a public lookup - search the license number or business name and you get status, tier, expiration, and usually complaint or discipline history. Do it for every finalist: lapsed licenses and borrowed numbers are more common than anyone admits. Complaint history deserves a careful read rather than a reflex - one resolved dispute in a decade is a business; a pattern of abandonment findings is a warning. If your pro works across a state line, ask which state issued the license and whether reciprocity covers your side; the permit office cares even if you don't.
References still work, too - ask for two from jobs like yours in the past year, and actually call. The question that gets honest answers: "would you use them again without getting other bids?" General vetting technique beyond plumbing lives in the contractor hiring guide.
Permits: When the Law Requires One (and Who Pulls It)
The jobs that always need permits
Water heater replacement, repipes, sewer or water-service work, gas lines, and moving drains or supply in a remodel are permit territory nearly everywhere. Like-for-like fixture swaps - a faucet, a toilet in the same spot - generally aren't. When in doubt, one call to the local building department settles it.
The homeowner-permit red flag
"You pull the homeowner permit and save money" is a flare, not a favor. Contractor-pulled permits attach the contractor's license to the inspection; homeowner permits shift the liability to you while the pro stays invisible to the county. Legitimate companies pull their own permits on permit-required jobs like water heaters as a matter of course.
Insurance and Bonding: The Paper That Protects Your House
Liability insurance pays for damage the plumber causes; workers' comp covers their tech's injury on your property so your homeowner's policy doesn't. Ask for a certificate of insurance and check the effective dates and coverage lines - a real company sends one without friction. Bonding, where required, adds a fund you can claim against for unfinished or non-compliant work.
The Handyman Line: What Non-Plumbers May Legally Touch
Most states allow unlicensed hands to do minor, like-for-like work - swap a faucet, replace a flapper, reset a toilet. The line lands where supply, drainage, gas, or anything permit-required begins. A handyman replacing your water heater isn't a bargain; it's unpermitted work with no license behind it, and it fails every test above at once.
Eight Questions That Sort Pros From Pretenders
- What license tier does the person on my job hold, and what's the number?
- Who pulls the permit - you or me?
- Can you send a certificate of insurance today?
- Who actually shows up - your techs or subcontractors?
- What's your labor warranty, in writing?
- Is the quote flat-rate or time-and-materials, and what does it exclude?
- How do you handle surprises found mid-job?
- Can you give two references from jobs like mine?
The answers that end conversations: "we don't really need a permit for this," "you can pull it yourself," any hesitation on insurance paperwork, and warranty terms that live only in conversation. Fair pricing context for judging their numbers lives on the plumber cost guide.
Your Shortlist, Built the Right Way
Three companies, licenses verified in the lookup, insurance certificates received, permit answers clean - then collect bids on an identical written scope and compare line by line. Or skip the legwork you've just learned: the top-rated plumbing companies directory pre-verifies licensing and insurance, with reviews and direct contact for exactly this shortlist.