Delaware to Illinois: master plumber license reciprocity
Illinois has no reciprocity agreement with Delaware. A Delaware master plumber applies by endorsement.
Reference only, not legal advice. Rules change; confirm with the licensing board before you apply. Full disclaimer.
Licensure by examination for out-of-state plumbers (225 ILCS 320/17(b)); exam waiver under 17(a) only where a reciprocal arrangement exists
The board reviews your out-of-state credentials case by case. Some exam is usually still required, often only a law or code exam.
A plumber licensed or registered by another state or municipality applies to IDPH under Section 17 of the Plumbing License Law. Under 17(b), if the State Board of Plumbing Examiners finds the origin jurisdiction's licence requirements 'substantially equal to the requirements for an Illinois Plumber's license' but that jurisdiction has no reciprocal agreement with Illinois, the applicant 'may apply for and be issued an Illinois Plumber's license provided that the applicant successfully passes the Illinois plumber's examination and pays the required fees'; the out-of-state licence stands in for the four-year Illinois apprenticeship that Section 10 otherwise requires. Under 17(a), the exam is waived only if the applicant is at least 21, the Board finds the origin requirements were substantially equal at the date of the origin licence, and the origin state accords the same privilege to Illinois plumbers; IDPH publishes a reciprocity form only for City of Chicago licensees and names no partner state, so this file treats every state origin as the 17(b) exam route. The Illinois examination is a single IDPH-administered test of planning and design, manual skills and the Illinois Plumbing Code, offered at least every three months, with the application due 30 days before the exam date. An origin licence whose requirements are not substantially equal gives no advantage; the applicant must complete the Illinois apprentice route. Once licensed, the plumber renews every April 30 with four hours of CE and must register a Plumbing Contractor (insurance and $20,000 bond) to contract for work.
Adm. The task brief cited 225 ILCS 320 Section 13 for out-of-state licensure; the operative section is 17 (Section 13 covers re-examination).
At a glance
- Trade exam
- Required
- Law / code exam
- Not required
- Out-of-state hours
- Count toward eligibility
What you must already have
- Your Delaware license must be active and in good standing.
- State Board of Plumbing Examiners finds the origin jurisdiction's plumber licence requirements substantially equal to the requirements for an Illinois Plumber's license (17(b)); for an exam waiver under 17(a) the requirements must have been substantially equal at the date of the origin licence and the origin state must accord the same privilege to Illinois plumbers
- At least 21 years of age (statutory condition for licensure without examination under 17(a) only)
- Two years of high school or equivalent (225 ILCS 320/10(2)(c) applies to all examination applicants)Whether IDPH requires 17(b) applicants to document this separately was not confirmed; it is a general examination prerequisite.
What you'll do to get licensed in Illinois
- 1Application fee. Pay the application fee. Examination application fee set by IDPH rule (68 Ill. Adm..
- 2Trade exam. Pass the destination's trade exam. Illinois plumber's examination administered by IDPH with the State Board of Plumbing Examiners: planning and design of plumbing systems, manual plumbing skills, and the Illinois Plumbing Code (77 Ill. Adm. Code 890); held at least once every three months; required under 17(b) unless the Board grants a 17(a) waiver.
- 3Exam fee. Pay the exam fee (if applicable). Re-examination fee if the exam is failed (Examination Retake Form filed 30 days before the next date); amount not confirmed.
- 4License fee. Pay the license or certificate fee. Fee, eligibility details, and processing steps are not published in a form we can list here. Please see the sources on this page to find out more..
- 5Other. Verification of the out-of-state plumber licence or registration for the Board's substantial-equivalence review; child-support certification required on all IDPH applications.
- 6Continuing education. Complete continuing education. 4 hours of IDPH-approved continuing education each year as a condition of every renewal after the first licence (225 ILCS 320/3(1)).
- 7Contractor license. Hold or obtain a contractor license (if applicable). Plumbing Contractor registration with IDPH (annual, expires 30 September) to perform plumbing for others; a licensed plumber must be the sole proprietor, a partner or a corporate officer (225 ILCS 320/13.1).
- 8Insurance. Carry the required insurance (if applicable). For Plumbing Contractor registrants: general liability at least $100,000 per occurrence and $300,000 aggregate bodily injury, property damage $50,000 (or $300,000 combined single limit), workers' compensation with $500,000 employer's liability (225 ILCS 320/13.1(4)).
- 9Surety bond. Post a surety bond ($20,000) (if applicable). For Plumbing Contractor registrants: $20,000 indemnification bond or letter of credit (225 ILCS 320/13.1(5)).
What you'll need to buy or arrange
Exam preparation
Most boards contract PSI, Prov, or ICC for exams. Check which code edition the exam is written to before buying a prep course.
- Trade exam
Continuing education
Renewals usually need approved CE hours, often on the latest NEC. Reciprocal licensees are rarely exempt.
- Continuing education
Liability insurance
Some states require proof of general liability or workers' compensation coverage at licensing time.
- Insurance · if applicable
Surety bond
A license or contractor bond is bought from a surety, not the state. Price is a small percentage of the bond amount and depends on your credit.
- Surety bond · $20,000 · if applicable
How Illinois licenses master plumbers
Illinois master plumber · “Plumber (Illinois licensed plumber)”
State license plus local requirements
Illinois' only full plumbing credential is the Plumber licence issued by the Department of Public Health; it is the state's equivalent of a master licence because a licensed plumber may plan, design, install and inspect all plumbing, sponsor up to two apprentices, and serve as the licence-holding member or officer of a registered Plumbing Contractor. The standard route is four years (48 to 72 months) as an Illinois licensed apprentice plumber or completion of an approved college/trade-school plumbing course, two years of high school or equivalent, an application filed at least 30 days before an exam date, and passing the IDPH-administered examination (held at least quarterly), which covers planning and design, manual skills, and the Illinois Plumbing Code (77 Ill. Adm. Code 890). Licences expire every April 30 and renew annually with four hours of continuing education. The City of Chicago runs a parallel plumber licence under Section 16 of the Act, and by statute a plumber licensed by either IDPH or Chicago may work anywhere in Illinois, so the two licences are alternatives rather than stacked requirements. Out-of-state plumbers are handled under Section 17: without examination only where the origin state's requirements were substantially equal at the time of licensure and that state reciprocates with Illinois (no state partner is named by IDPH), otherwise by passing the Illinois plumber's examination.
How local licensing works in Illinois
Chicago. Section 16 of the Plumbing License Law lets a municipality of 500,000 or more (only Chicago qualifies) adopt an ordinance 'substantially the same' as the Act with equivalent education or experience requirements and run its own board of plumbing examiners; within Chicago the state Act then does not apply except as the Act provides. The City of Chicago Department of Buildings issues that plumber licence. Section 16(2) provides that 'any person licensed as a plumber pursuant to such ordinance, or licensed by the Department under this Act, may engage in plumbing anywhere in this State', so an IDPH licence is valid in Chicago and a Chicago licence is valid in the rest of Illinois; Section 13.1(9) also accepts a Chicago plumber licence for state Plumbing Contractor registration. IDPH separately publishes a 'Plumber's License: Application for Reciprocity for the City of Chicago Licensees' for Chicago plumbers who want the state card as well. Local governments may adopt a plumbing code at least as stringent as the State code, require permits, and employ licensed plumbers as inspectors (Sections 18, 36, 37), but they cannot require a separate individual plumber licence.
- Chicago (Department of Buildings, plumber licence under 225 ILCS 320/16)
Common questions
- Do I have to take the Illinois master plumber exam if I'm licensed in Delaware?
- Yes. Illinois requires the trade exam on this path.
- Do my Delaware work hours count in Illinois?
- Yes. Documented out-of-state experience counts toward Illinois's eligibility requirements.
Sources
- IDPH - Plumber's License: Application for Reciprocity for the City of Chicago Licensees (form dated 2016-04-26) · Illinois Department of Public Health · Form · verified September 16, 2026
- IDPH - Plumber's License: Application for Examination (form dated 2021-06-24) · Illinois Department of Public Health · Form · verified September 16, 2026
- Illinois Department of Public Health - Plumbing (licensing requirements, renewal, apprentices, contractors, forms) · Illinois Department of Public Health (IDPH), Division of Environmental Health · Agency Page · verified September 16, 2026
- Illinois Plumbing License Law - full text (225 ILCS 320) · 225 ILCS 320/3, 320/8, 320/9, 320/10, 320/11, 320/13, 320/13.1, 320/14, 320/30, 320/42 · Illinois General Assembly · Statute · verified September 16, 2026
- Illinois Plumbing License Law, Sec. 16 - Municipal plumbing examiners in cities of 500,000 or more (City of Chicago) · 225 ILCS 320/16 · Illinois General Assembly · Statute · verified September 16, 2026
- Illinois Plumbing License Law, Sec. 17 - Out-of-state and municipal licensees (reciprocity and licensure by examination) · 225 ILCS 320/17 (P.A. 101-541, eff. 2019-08-23) · Illinois General Assembly · Statute · verified September 16, 2026
Verified dates are when a person last opened each source and confirmed the facts above. Cite the board, not us.