A journeyman plumber in Tulsa has been working for a contractor for years and decides it is time to pull permits under their own name. They pass the Plumbing Contractor and Natural Gas exam and start celebrating. Then the Construction Industries Board explains that a contractor license needs a second exam: Plumbing Business and Law. Different book, different topics, and its own passing line.
Here is the plain answer. In Oklahoma, a contractor license in electrical, mechanical or plumbing takes two exams: the trade exam and a separate Business and Law exam for that trade. Journeyman licenses take the trade exam only. PSI gives all of them for the Oklahoma Construction Industries Board, and all of them are open book.
Two things are changing this fall, and both matter if you test soon. The plumbing trade exams drop from a 75 percent pass mark to 70 percent on November 1, 2026. And the code books move from the 2018 editions to the 2024 editions, with the 2018 books no longer allowed after December 14, 2026.
The figures below come from PSI’s Oklahoma electrical, mechanical, roofing and plumbing candidate information bulletin (effective September 11, 2026), read today.
The exams at a glance
Electrical
- Unlimited Electrical Contractor: 100 scored items, 240 minutes, 70 percent.
- Electrical Business and Law: 50 scored items, 120 minutes, 70 percent (35 correct).
- Unlimited Electrical Journeyman: 100 scored items, 240 minutes, 70 percent.
Plumbing
- Plumbing Contractor and Natural Gas: 85 scored items, 180 minutes. 75 percent (64 correct) until November 1, 2026, then 70 percent (60 correct).
- Plumbing Business and Law: 50 scored items, 120 minutes, 75 percent (37 correct).
- Plumbing Journeyman and Natural Gas: 85 scored items, 180 minutes. Same change: 64 correct until November 1, 2026, then 60.
Mechanical (HVACR)
- HVACR Contractor Unlimited: 90 items, 240 minutes, 70 percent (63 correct).
- Mechanical Business and Law: 50 items, 120 minutes, 70 percent (35 correct).
- HVACR Journeyman Unlimited: 70 items, 180 minutes, 70 percent (49 correct).
Up to ten unscored experimental questions may be added to any exam. The time spent on them does not count against your clock. The bulletin also covers limited, residential, refinery, natural gas, process piping, sheet metal and refrigeration licenses, each with its own numbers.
The plumbing pass mark is changing
The plumbing trade exams have needed 75 percent, more than the 70 percent on the electrical and mechanical papers. The current bulletin says that changes on November 1, 2026. On an 85-item paper, that is the difference between 64 correct and 60.
Two details people miss:
- Plan by your test date. If you sit before November 1, expect the 75 percent line.
- Plumbing Business and Law is not listed as changing. The bulletin still shows 75 percent, 37 of 50. Practice that paper to 75.
Code books are in transition
This is the other moving part. The bulletin lists both the 2018 and 2024 editions, with Oklahoma revisions, for the main codes:
- Plumbing: the 2018 International Plumbing Code and International Fuel Gas Code. The 2024 editions can be used starting October 8, 2026.
- Mechanical: the 2018 or 2024 International Mechanical Code and International Fuel Gas Code. The 2024 editions can be used starting September 14, 2026.
- For all of them: as of December 14, 2026, the 2018 editions will no longer be used or allowed.
- Electrical: the 2023 National Electrical Code, as revised and adopted in Oklahoma. NEC handbooks and spiral-bound copies are not allowed in the test center.
If you are buying books now and testing after mid-December, buy the 2024 editions. If you test before then, check which edition your questions will follow on the bulletin you are issued. The bulletin’s rule is that code questions are based on the edition listed, while other references can be later editions.
Business and Law is a separate exam per trade
Each trade has its own Business and Law paper: electrical, mechanical and plumbing. They share a topic structure, bidding and estimating, project management and supervision and so on, but each uses that trade’s own Oklahoma rules.
The electrical version, for example, allows the Construction Industries Board’s Unofficial Administrative Rules and Courtesy Exam Study Aids book, the Oklahoma Electrical Industry Regulations (Title 158, Chapter 40), the fine schedule (Title 158, Chapter 10) and the Oklahoma Electrical License Act. Trade skill does not help much here. Knowing where the answer sits in those books does.
Our Oklahoma Business & Law exam prep covers the shared outline.
Before the exam: experience
PSI only schedules you once the board approves you, and the board approves you on experience. The rules sit in the Oklahoma Administrative Code, a separate chapter for each trade.
- Electrical journeyman (OAC 158:40-7-1): 8,000 hours of experience, with 4,000 of them commercial or industrial.
- Plumbing journeyman (OAC 158:30-9-1): three years, or the education substitutions listed in that section. A plumbing contractor adds a contractor-level year on top.
- HVACR journeyman (OAC 158:50-9-1): three years at 2,000 hours a year, or the education paths in that section. The HVACR contractor adds one more year.
Check the current rule text with the board before you apply. If your hours are borderline, an application that comes back short costs you more time than any exam.
The bulletin itself makes one point worth repeating: if you pass, the Construction Industries Board issues the license. But you only get to the exam once the board has signed off on your application.
What you can bring
- Your own references, as listed for your exam. You bring them.
- Marking: permanent tabs. Sticky notes and other temporary tabs must come out before the exam starts.
- Downloaded references must be spiral bound, hole-punched in a binder, or stapled in the corner.
- Calculator: silent, non-printing and non-programmable. A magnifying glass is available on request.
When references conflict, the bulletin says a legal requirement such as a code or law beats any other reference, and the Oklahoma version beats the national one.
Retakes and results
- Results: on screen right after the exam. A fail comes with a diagnostic report by topic.
- After a first fail: wait 30 days.
- Electrical exams: every later retest is also a 30-day wait.
- All other exams: from the second fail on, the wait is 90 days.
- Eligibility: the bulletin says there is no expiration on your eligibility.
Each attempt is a separate paid registration, whether it is your first or a retake.
How to prepare
- Plan for both exams from the start if you want a contractor license. The trade exam alone does not get you there.
- Pick your code edition on purpose. Match it to your test date and the December 14 cutoff.
- Practice to the right line. 75 for plumbing before November 1 and for Plumbing Business and Law. 70 for the rest.
- Tab by the outline. Permanent tabs on the sections the topic list points to.
- Time yourself. 180 minutes for 85 plumbing items is a little over 2 minutes each, and open-book time disappears fast.
Questions candidates ask
Is the Oklahoma plumbing exam 80 questions?
Not on the current bulletin. The plumbing contractor and journeyman exams are 85 scored items in 180 minutes.
Do journeymen take Business and Law?
No. Business and Law is for contractor licenses. Journeyman licenses take the trade exam.
Which electrical contractor exam do I take?
Oklahoma has limited, unlimited and residential electrical contractor exams. See our Oklahoma Electrical Contractor exam prep and confirm your classification with the board before you schedule.
Next step
Find your license on our Oklahoma exam prep page. If you are going for a plumbing contractor license, start with our Oklahoma Plumbing Contractor exam prep.