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NoVA & DC Plumbing Map

Job · Checking a plumber's license

How to check a plumber's license

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In DC, the Department of Licensing and Consumer Protection licenses plumbers; in Virginia, the Department of Professional and Occupational Regulation does; look the license up yourself before you sign.

Revised November 3, 2026 · who makes this map

The Moses Hepburn Rowhouses seen along North Pitt Street from the north
North Pitt Street, Old Town Alexandria.
Where this differs
PlaceWhat happens thereTurn to
DCDLCP's Board of Industrial Trades covers plumbers and gasfitters, in four tiers: apprentice, journeyman, master and contractor. The DC Department of Buildings pulls license data into the permit application.Sheet 1
ArlingtonVirginia's state board licenses the contractor. We could not read the county's permit pages; ask the county what it requires of the applicant.Sheet 6
AlexandriaThe city page on backflow preventers says to hire a plumber holding licenses from both the State and the City. Ask the city's permit office how to verify the city side.Sheet 8
Fairfax CountyThe county's plumbing permit page links to the state license lookup for verifying a contractor.Sheet 17
Towns and small citiesThe state license still applies. We could not confirm separate local licensing in Vienna, Herndon, Falls Church or the City of Fairfax; ask each.Sheet 11

Pick the right board

Licensing follows the state or district where the work happens, not the plumber's home address. For a job in DC, the license that counts is a DC license. For a job in Arlington, Alexandria, Fairfax or the towns, it is a Virginia license. A contractor with a license on one side of the river does not hold one on the other unless the contractor shows it. Never assume.

This map does not cover Maryland.

In DC

DLCP's Board of Industrial Trades covers plumbers and gasfitters. It offers an online license verification. The tiers are apprentice, journeyman, master and contractor. DC Water states that a registered master plumber must clear a lateral when the main is clear, so for sewer work in DC, a master plumber is the person to ask for. The Department of Buildings' permit form asks for the master plumber's license number, and its Permit Wizard checks it against DLCP records. If the number you are given does not validate, that is a reason to stop and ask questions.

DLCP's pages would not open for us, so the tier list comes from a search listing. Check the board's own page for the current rules.

In Virginia

The Board for Contractors, part of DPOR, licenses contractors. Virginia sets three classes by the size of a project. Class C covers a single job over $1,000 and under $30,000. Class B covers $30,000 up to $150,000. Class A is $150,000 and above, and 12-month totals count too. Plumbing appears on applications as the specialty code PLB. DPOR also regulates tradesmen, such as journeymen, under its own rules. The license lookup is on DPOR's site.

DPOR's pages would not open for us, so some details of the specialty and tradesman rules come from search listings and the state code. Verify on the lookup itself.

To see what to look for on a firm's website, here is one in southeastern Pennsylvania, outside this map: a plumbing company's service page at Central Plumbing (that company is connected to the team behind this map).

What to compare

1. The name on the license matches the name on the contract and the permit. 2. The license status is active, not expired. 3. The class or tier covers the size of your job. 4. The specialty includes plumbing. 5. The permit lists that license holder, not a different person.

A firm's website may mention license numbers. Treat that as a claim to confirm on the lookup. Our link above shows an example of the kind of services page a company publishes; it is not an endorsement and the firm is not in this region.

Permits and who pulls them

In Fairfax County, the property owner can obtain a permit, but the county strongly recommends the licensed contractor do it. If a contractor is not listed on the application, the county requires a License Exemption Affidavit. That form tells you something: an applicant either holds a license or is claiming an exemption. See permits by place for each office, and sewer lateral repair for the work most likely to need a specialist.

For gas work, the plumber should also be licensed to do it. Anything on a gas line is licensed-trade work, never a home project; see gas water heaters.

Check your own address

  1. Decide the jurisdiction from your tax record, then pick DLCP for DC or DPOR for Virginia.
  2. Look up the license by name on the board's lookup, and screenshot or print the result.
  3. Ask for the license number in writing on the estimate, and match it.
  4. Confirm the permit will be issued in that holder's name.
  5. Walk away if the answer is "we don't pull permits."

More on checking an address

Survey notes: sources for this page