How to Check a Plumber's License in Minnesota

Fall is quote season. The water heater that's been making noise all summer, the drain that backs up every few months, the bathroom you finally want to redo before winter — this is when St. Paul homeowners start collecting numbers from plumbers they've never met.

Most people check reviews. Far fewer check the one thing the state actually tracks: whether the business is licensed to do plumbing in Minnesota at all. It takes about five minutes, it's free, and it's the single cheapest piece of protection you have before you hand anyone a deposit.

Here's how to do it, what the record tells you, and what it doesn't.

First, understand who holds which license

This trips people up, so it's worth a minute. In Minnesota, plumbing licensing works in layers — and the most important license usually isn't the one belonging to the person who shows up at your house.

The company needs a plumbing contractor license from the Minnesota Department of Labor and Industry (DLI) to do plumbing work in any community with more than 5,000 people — which covers St. Paul and most of the surrounding suburbs. To get and keep that license, DLI requires the company to file a $25,000 surety bond, carry liability insurance, and stay compliant with workers' compensation requirements.

The company also has to name a responsible master plumber — someone holding an active master plumber license who is accountable for all of the plumbing work that company performs.

The person doing the work doesn't need their own contractor license. Under DLI's rules they need to be a licensed journeyworker or master plumber, a plumber registered with DLI as a "registered unlicensed plumber," or an apprentice enrolled in a registered plumbing apprenticeship program. All three are legitimate. An apprentice working for a licensed contractor is exactly how the trade is supposed to train people.

How to look up a license (about five minutes)

1. Get the exact business name. Use the name printed on the quote or invoice, not what's on the side of the truck. If the quote doesn't show a business name, ask for it.
2. Go to DLI's license lookup. Start at dli.mn.gov and search for the license lookup, or call DLI at 1-800-DIAL-DLI (342-5354) if you'd rather ask a person.
3. Search the company name. You're looking for a plumbing contractor license.
4. Check the status and expiration date. "Active" with an expiration date in the future is what you want. Expired, suspended, or not found are all worth a direct question before you go further.
5. Match the details. The business name and city on the record should line up with the quote. A mismatch isn't automatically a problem — some businesses operate under an assumed name — but it's a fair thing to ask about.

You can search individual plumbers by name the same way if you want to confirm the person doing the work, but for most homeowners the company check is the one that matters.

The St. Paul permit question most people skip

Licensing and permits go together. The City of Saint Paul requires licensed plumbing contractors to obtain permits for plumbing work, and on a normal job the contractor pulls that permit and builds the fee into the quote. The permit is what triggers a city inspection — someone other than the installer checking that the work meets the Minnesota Plumbing Code.

So a good question to ask on any quote is simply: "Will you be pulling the permit for this?" A licensed contractor who does this work regularly will have a quick, confident answer.

The red flag: "Just pull the permit in your name"

St. Paul does let owner-occupants pull their own plumbing permit for a one- or two-family home they live in. But that permit is for homeowners doing the work themselves. The city's homeowner affidavit says the permit holder will personally buy the materials and perform all of the labor.

If someone offering to do the job for you suggests you pull the permit in your name instead, that's one of the clearest warning signs you'll get. It often means they can't pull one themselves. It also puts the work — and the inspection responsibility — in your name. Walk away from that one.

If you're ever unsure whether a job needs a permit, St. Paul's Department of Safety and Inspections can answer that directly at 651-266-8989. (One wrinkle worth knowing: sewer work outside the house goes through the city's Public Works sewer utility rather than DSI — relevant if you're dealing with roots in your sewer line.)

Other questions worth asking before you sign

• Can you send me a certificate of insurance? (Reputable contractors send these routinely.)
• Is this quote in writing, with the scope of work spelled out?
• Does the price include the permit and any required code updates?
• How much is the deposit, and when is the rest due?
• Who will actually be doing the work, and who do I call if something goes wrong afterward?

None of these should offend a legitimate plumber. If a question gets a defensive reaction instead of an answer, that tells you something too.

What a license doesn't tell you

An active license means the business met the state's requirements to do plumbing work. That's the floor, not a quality rating. It doesn't tell you:

• Whether the price is fair
• How well the company communicates or how fast it shows up
• Whether their recommended fix is the right one for your house

That's why comparing more than one quote on bigger jobs still matters. Two licensed contractors can look at the same problem and propose very different solutions at very different prices. For a sense of typical ranges on one of the most common fall jobs, our water heater replacement cost guide breaks down what drives the number — including the permit.

The short version

1. Get the business name from the quote.
2. Look it up with DLI and confirm an active plumbing contractor license.
3. Ask whether they're pulling the permit.
4. Don't pull a homeowner permit for someone else's work.
5. Get it in writing, and compare quotes on bigger jobs.

It's the same license check we run with DLI before any plumber receives requests through The Plumbing Pipeline — and it's worth doing yourself, too, no matter how you found your plumber.