Delaware Plumbing License: What Applies and What Does Not
What Delaware requires of a plumbing business in 2026, what the LLC has to file first, and where the license and the entity are two separate steps.
By Edmond Hui · Last updated: September 2026
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Delaware plumbing licensing at a glance
| State credential required for this work? | Yes, statewide |
| What it is called | Master Plumber |
| Who issues it | State Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners |
| Must the business itself be licensed? | No, individuals hold it |
Does a plumbing business need a license in Delaware?
Delaware issues the Master Plumber for plumbers.
Delaware licenses plumbing statewide through the Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners in the Division of Professional Regulation, which issues the master plumber license to individuals. The Board issues no license to a company, and other Delaware business registrations such as the Division of Revenue business license apply to a plumbing business as they do to any other.
The license attaches to qualified individuals. Delaware does not require the plumbing business itself to hold one.
24 Del. C. 1802(10) defines the license the Board issues as certifying that the holder is a master plumber, a master HVACR licensee or a master HVACR restricted licensee, all of which 1802(13) and 1802(11) define as individuals. An apprentice, journeyman or mechanic may provide plumbing services under a master plumber who is that individual's employer or is employed full time by the same business entity, so the company works through a licensed master plumber rather than holding a license itself.
This records what Delaware publishes, not a determination about your business. Scope, thresholds and local requirements are set by the issuing body, so confirm with them before you bid or file.
Source: Delaware Code Title 24, Chapter 18, Subchapter II, Plumbers. Verified 2026-09-03.
What the LLC has to do first
Several states license the plumbing company separately from the individual plumber, so the LLC and the license are two filings, not one.
The entity filing is separate from anything the license requires. In Delaware it is made with the Delaware Division of Corporations. File directly with the state here. The order matters wherever the license is issued to the company rather than to a person: the entity has to exist before an application can name it.
Forming an LLC as a plumbing business in Delaware covers the filing itself, step by step.
Insurance Delaware plumbers are asked to show
Plumbing license and registration schemes commonly require proof of general liability cover, and water damage from a failed connection is the claim these policies are bought for.
We do not publish Delaware premium figures for this trade, so nothing here is a quote. Our business insurance guide for plumbers covers what each policy does and does not pay for.
This guide is general information, not legal or tax advice, and reading it does not create an attorney-client relationship. It reports what each state licensing board publishes for this trade, with the sources this page cites. It cannot tell you whether your own work needs a licence: that turns on the scope of the job, the value of the contract, and the city or county you work in, which commonly adds its own registration on top of the state's. Confirm your own position with the board named on this page and with your local building or business licensing office before you bid or start work.
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Edmond Hui · Founder, MyStateLLC
Edmond Hui is a software engineer and serial entrepreneur based in New York who has founded multiple online businesses across e-commerce, media, and information publishing. Before transitioning into tech, he spent years as a commercial real estate professional closing deals totaling over 100,000 square feet, giving him firsthand experience with business formation and entity structuring. He built MyStateLLC to provide the free, state-specific LLC guidance he wished existed when forming his own companies.