Illinois Plumbing License: What Applies and What Does Not
What Illinois 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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Illinois plumbing licensing at a glance
| State credential required for this work? | Yes, statewide |
| What they are called | Licensed Plumber, Licensed Apprentice Plumber, Plumbing Contractor Registration, Irrigation Contractor Registration, Retired Plumber |
| Who issues it | Illinois Department of Public Health |
| Must the business itself be licensed? | Yes |
Does a plumbing business need a license in Illinois?
Illinois issues 5 license classes for plumbers.
Illinois licenses plumbers statewide under the Illinois Plumbing License Law, administered by the Illinois Department of Public Health. Individuals hold the plumber or apprentice plumber license, and the business that performs plumbing for others registers separately as a plumbing contractor.
The plumbing business itself must be licensed or registered, not only the people doing the work.
A plumbing business registers annually with the Department as a plumbing contractor. The Department's registration form is filed in the business name and asks whether the business is a sole proprietorship, partnership, or corporation or limited liability company, and the named Plumber of Record must be the sole owner, a partner, an officer of the corporation, or a manager or member of the LLC.
This records what Illinois 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: 225 ILCS 320/3, Illinois Plumbing License Law. 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 Illinois it is made with the Illinois Secretary of State. 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 Illinois covers the filing itself, step by step.
Insurance Illinois 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 Illinois 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.