Plumbing License Requirements in Illinois

General Scope and Professional Requirement

Almost all professional plumbing work in Illinois requires you to meet plumbing license requirements in Illinois. If you install, repair, maintain, alter, or extend any plumbing system for compensation, you must hold the proper state license or registration. The law applies regardless of project dollar value or property type.

Definition and Exceptions

The legal definition of “plumbing” is broad. It covers installing, repairing, or modifying water systems, fixtures, sanitary drains, venting, and related piping from the water source to and within buildings. This includes work on water supplies, drainage, waste and vent systems, water heaters, lawn sprinklers, and sometimes backflow devices. However, the law specifically excludes drain-laying, drilling private wells, installing or servicing water softening equipment, and minor repairs that do not involve changing or rerouting pipes.

Employees, Contractors, and Exemptions

Contractors must be aware of the clear distinction in the plumbing license requirements in Illinois between direct employees, business owners, and independent contractors. If you are an employee of a plumbing business, you must be a licensed plumber or a registered apprentice under supervision. Businesses providing plumbing services must employ or designate at least one licensed plumber as an officer, and register as a plumbing contractor. Employees performing only maintenance work and not holding out their services to the public do not need to register as contractors, but there must be no contracting with outside clients. Similarly, irrigation contractors (for lawn sprinkler systems) have their own registration process and may employ licensed plumbers to perform system connections.

Owner-Occupant Exemption and Prohibited Work

Exemptions are narrow. The only notable exception is for owner-occupants of single-family homes performing plumbing work on their own home. To qualify, you must actually live in the home for at least six months, follow State Plumbing Code requirements, and complete all work yourself. No unlicensed helpers are allowed, and you still must call for required inspections. Handymen, unlicensed workers, and general contractors are never permitted to do plumbing work for clients without holding the proper plumbing license in Illinois. In short, if you work for pay or compensation on plumbing in any setting besides your own house, you must be licensed or properly registered.

Levels and License Classifications

There are several clearly defined plumbing license requirements in Illinois, separated by level of skill, function, and business purpose. Each license type has specific scope and prerequisites set out by state law and the Illinois Department of Public Health.

Descriptions and Prerequisites

• Apprentice Plumber: This license is for those learning the trade under supervision. Apprentices perform plumbing work but only under the direct oversight of a licensed plumber. Registered apprenticeships must meet specific training and documentation requirements.

• Plumber: After meeting the experience and education criteria and passing the state exam, you can be licensed as a plumber. Only licensed plumbers may independently plan, install, repair, or maintain plumbing systems for the public.

• Plumbing Contractor: If you want to operate a plumbing business or contract plumbing projects, you must register as a plumbing contractor. Contractor registration is not a separate technical license. Instead, it is a business registration that requires you to already hold a plumber license, maintain specified insurance, and submit the required forms to the state. Plumbing contractors can hire employees, enter contracts, and supervise plumbing work.

• Irrigation Contractor: Illinois separately registers irrigation contractors, who are allowed to work only on lawn sprinkler systems. Irrigation contractors may employ licensed plumbers for specific system connections, but their registration does not authorize other types of plumbing.

• Retired Plumber: This is a special license category for individuals who are no longer active in the plumbing business but want to maintain a surrendered status for their license. Retired plumbers cannot legally perform plumbing work.

Paths to Registration

To register as a plumbing contractor, you must first hold an active plumber license for at least 60 days. You cannot become a contractor without passing the plumber examination and meeting all apprenticeship or experience requirements. No apprenticeship or plumber license is needed for irrigation contractor registration, but your scope of work is much narrower.

Main Process for Plumber Licensure

To meet plumbing license requirements in Illinois, you must follow several clearly defined steps, whether seeking an apprentice, plumber, or contractor status. The main process for state plumber licensure is as follows:

1. Meet Education and Experience Requirements: First, ensure you have completed at least two years of high school or the equivalent (10 high school credits). Most importantly, accumulate four years of experience as an Illinois-licensed apprentice plumber, complete an approved training program equivalent to at least 2,800 hours, or verify equivalent out-of-state experience (at least 1,400 hours per year worked).

2. Prepare and Submit Application: Download the plumber license exam application form from the IDPH website. Prepare your application with all required supporting documentation (proof of experience, education, citizenship/intent, photo, and, if needed, notarized forms). Include any required fee and mail the completed application to the address provided. Your application must be postmarked at least 30 days before your requested exam date.

3. Sit for and Pass the State Plumber's Exam: After your application is accepted, IDPH will contact you regarding the next available exam date. Exams are held at least every three months. Attend the exam as scheduled. If you require a religious exemption from having your photo taken, you must be fingerprinted instead.

4. Receive Your Plumber License: Upon passing the exam and paying any license fee, you will receive a photo identification card showing your Illinois plumber license number. This ID must be kept on you while working.

5. Register as a Plumbing Contractor (Optional): After you have held your plumber license for at least 60 days, you may apply for plumbing contractor registration. Submit the required contractor registration application, proof of insurance, business details, surety bond (if required), and pay the applicable fee. Contractor registration must be renewed annually by September 30.

Application for Apprentices

To become a registered apprentice, you must enroll in an approved apprenticeship program and file the apprentice registration form with IDPH. The apprentice status is valid for four years and may be extended for good cause. All apprentice work must occur under direct supervision of a licensed plumber, and the hours must be documented for future licensing.

Contractor Registration Details

If your goal is to run a plumbing contracting business, you must meet additional plumbing license requirements in Illinois for registration. These include holding an active plumber license, maintaining the required business insurance, and submitting an annual application prior to the last day of September each year. The Illinois Plumbing Contractor Registration Code sets out the required forms and documentation.

The state sets specific eligibility and supporting document rules as part of plumbing license requirements in Illinois. These requirements differ somewhat depending on the license or registration class, but all must be met in full before your application is approved.

Experience and Education

Applicants for the plumber exam must document either:

• Four years (at least 2,800 hours) as a registered apprentice plumber in Illinois

• Equivalent out-of-state plumbing experience, with official verification (must be at least 1,400 hours for each year claimed)

• Successful completion of a board-approved plumbing course equivalent to four-year apprenticeship

You must also show proof of at least 10 high school credits or completion of two years of high school (or equivalent education), as indicated by official transcripts or GED certificate.

Citizenship/Residency

Applicants must be either:

• A U.S. citizen, or

• An alien who has filed a declaration to become a citizen (requiring a notarized declaration form with your application)

This requirement is set by statute and enforced by IDPH on all initial license applications.

Application Documents

Your application must include:

• A recent passport-style photograph (or completed fingerprinting if religious objection to photographs)

• Proof of apprenticeship or training (completion certificates, employer verification, or course transcripts)

• Education records and citizenship status declaration

• All required documents must be submitted with the application package; incomplete packages will delay processing

Bond and Insurance for Contractors

If you are applying for plumbing contractor registration, you must provide proof of business insurance meeting state minimums:

• General liability insurance: minimum $100,000 per occurrence and $300,000 aggregate for bodily injury

• Property damage liability: $50,000 per occurrence or $300,000 combined single limit

• Workers’ compensation insurance with a $500,000 employer’s liability policy

• A surety bond is referenced in the registration code, but the amount and form are not specified in current published regulations (as of July 2026).

You must keep active insurance and bond coverage to maintain your registration or risk loss of contractor privileges.

Background Check and Fingerprinting

No general criminal background check is explicitly required in the current statutes or IDPH rules for licensing or registration. However, applicants who claim a religious exemption regarding personal photographs must submit to fingerprinting, which is used for identification during testing and licensing. IDPH may also request further identification or documentation to verify your identity for licensing.

Passing the state plumber’s exam is a core part of the plumbing license requirements in Illinois. Without successfully passing this examination, you cannot become a licensed plumber or register as a plumbing contractor.

The Board of Plumbing Examiners, working within the Illinois Department of Public Health, prepares and administers this written and (possibly) practical test. Official rules specify the following:

• The exam is scheduled at least once every three months, with additional dates scheduled as needed

• Applicants must submit their application and required documents at least 30 days prior to the exam date

• All applicants must appear in person with proper identification

• If you are exempt from photographs for religious reasons, fingerprinting is required instead

The state has not published information about the exact format, number of questions, content coverage, or time limit for the plumber’s exam. Nor is the passing score officially posted online. Third-party sources refer to both a written and practical section, and a passing score around 75%, but these details are not confirmed in statute or board rule as of July 2026. For retakes, you must submit a new application at least 30 days in advance. Original application fees are non-refundable. See the IDPH Plumbing Program for all exam updates.

Plumbing license requirements in Illinois include paying application, exam, and registration fees. However, official, current fee amounts are not posted on the Illinois Department of Public Health’s public sites as of July 2026.

• No official plumber exam application fee is published online. Some third-party sources mention $175 (for Illinois apprentices) and $225 (for out-of-state or Chicago applicants), but these amounts are not confirmed or posted by IDPH. Always verify at IDPH Plumbing Program.

• Plumbing contractor registration fees (both new and renewal) are not specified on the IDPH site or in the Illinois Plumbing Contractor Registration Code. The law requires fees "as set by rule," but the state has not posted these figures. Bond amounts, if applicable, also are not specified on public records. Verify all fees with IDPH.

• Continuing education providers and license restoration may require additional fees. Again, check official sources for each cycle.

Because official state fee schedules are not posted, contact the IDPH directly before submitting applications or payments. See the current IDPH Plumbing Program fee schedule for all payments and application forms.

The renewal process is clearly outlined in the plumbing license requirements in Illinois. All plumber and apprentice licenses must be renewed each year by April 30. Plumbing contractor registrations must be renewed annually by September 30.

Renewal Process

To renew your plumber or apprentice license:

• Submit the renewal application online or by mail as provided by IDPH

• Verify completion of all required continuing education hours (unless it is your first renewal cycle)

• Include the appropriate renewal fee (see above for note on currently unpublished fees)

For plumbing contractors, renewal includes submitting a valid plumber license number, updated proof of insurance and bond coverage, and the contractor registration renewal application. The registration must be renewed each year before September 30 to remain authorized to contract work or employ plumbers.

Continuing Education Requirements

Effective after your first license cycle, you must complete four hours of board-approved continuing education each year to maintain your plumber license. CE courses must:

• Be provided by a board-approved provider

• Be supervised by a licensed plumber instructor

• Cover state-approved topics relevant to public health, code, and plumbing practice

For apprentice plumbers, continuing education is not required for the first renewal, but will apply to future renewals. CE records must be available for audit by IDPH. Failing to complete CE can result in license non-renewal or civil penalties for unlicensed practice.

Late and Lapsed Renewals

If you miss your annual renewal deadline, you are prohibited from practicing plumbing until you reapply and are reinstated by IDPH. The law imposes civil penalties for unlicensed practice. If your license remains expired for more than five years, you may be required to complete the restoration application, pay additional fees, and possibly retake the licensing exam. Details for lapsed license restoration are not published as of July 2026. For late renewal information, always consult the IDPH Plumbing Program before working.

Illinois does not grant plumbing license reciprocity or license by endorsement from any other state. There are no formal recognition agreements in the statute or board rules. If you hold a plumbing license from another jurisdiction, your out-of-state experience may count toward the Illinois experience requirement (documented hours credited at 1,400 per year). However, you will still need to submit a full application, provide all supporting documents, and pass the Illinois plumber licensing exam to earn a license in Illinois. Contractors from outside Illinois cannot avoid testing and registration requirements by holding another state’s license. For the full details or possible updates, verify at the Plumbers Licensing Code.

• Illinois Department of Public Health Plumbing Program: Forms, applications, renewals, license lookup, and provider contacts

• Illinois Plumbing License Law – 225 ILCS 320: Full statutory text

• Plumbers Licensing Code – 68 Ill. Adm. Code 750: Full administrative rules on exams, CE, applications

• Plumbing Contractor Registration Code – 77 Ill. Adm. Code 894: Regulations governing contractor business registration