South Carolina Plumber License Exam

Three Exam Systems, Not One

South Carolina plumber exams aren't administered by a single agency. Three separate credentialing tracks use two different testing vendors, and the scheduling process for each one follows a different sequence. Getting confused about which exam goes through which vendor — or trying to schedule before you're eligible — is one of the most common derailments in the licensing process.

PSI Exams: Contractor Licensing

PSI Services administers the exams for both state contractor license tracks:

Residential Specialty Plumbing (RBC track): Two exam portions — a trade exam and a Business, Law, and Project Management exam. Both are open-book, meaning you can bring approved reference materials including the International Plumbing Code with South Carolina amendments.

Commercial Mechanical Plumbing PB (CLB track): Two exam portions — a commercial plumbing trade exam and the South Carolina Business Management and Law for Commercial Contractors exam. Also open-book with approved references. The passing threshold is 70% or higher on each portion.

PSI exam fees run approximately $75 per portion, so expect to pay around $150 total for both portions on either track.

The Sequence Difference That Trips People Up

Residential (RBC) — eligibility first, test second. You cannot schedule PSI exams until the Residential Builders Commission has reviewed your application and issued an official Examination Eligibility Letter. Submit your application with the $135 processing fee, credit report, SLED background check, and experience affidavits. Wait for approval. Then register with PSI using your eligibility letter.

Commercial (CLB) — test first, apply second. No board pre-approval needed. Register directly with PSI, pay the exam fees, and take the exams. Once you pass, submit your contractor license application (Doc. 165) to the CLB with your pass sheets attached.

If you're on the residential track and try to register with PSI before receiving your eligibility letter, PSI will block the registration. If you're on the commercial track and submit your application before passing exams, the CLB returns it unprocessed.

Prov Exams: Trade Certification

The CAGC SC Trades Certification Program uses Prov (not PSI) for individual Journeyman and Master Plumber trade certification exams. The process:

1. Submit an application and $35 processing fee to the CAGC Foundation
2. CAGC reviews your experience documentation
3. Upon approval, CAGC issues a testing voucher code
4. Register with Prov using the voucher code

The Prov exam fee is $100. Both Journeyman and Master exams are open-book — approved code references and trade calculators are permitted.

Remote Testing Through Prov Examroom

Prov offers remote online proctoring through its "Examroom" service. If you choose the remote option, review the system-compatibility and webcam requirements before scheduling.

Retake Policies

PSI (contractor exams): If you fail, reschedule directly with PSI and pay the testing fee again.

Prov (trade certification exams): If you fail, pay a $35 retesting fee to the CAGC Foundation to receive a new Prov testing voucher. Then register with Prov again.

Reference Materials and Preparation

All SC plumber exams are open-book, which changes the preparation strategy compared to closed-book exams in other states. The key is knowing where information lives in the code — you don't need to memorize pipe sizing tables, but you do need to find them quickly under time pressure.

The primary reference is the International Plumbing Code with South Carolina amendments (currently the 2021 edition). Tab your code book and practice navigating to frequently tested sections: fixture unit calculations, DWV sizing, pressure testing requirements under Section 312, and backflow prevention.

The law and business management portions test South Carolina-specific statutes, lien law, contract requirements, and OSHA safety standards. These sections require familiarity with state-specific rules that aren't in the plumbing code.

The South Carolina Plumber License Guide maps out the complete exam logistics for all three tracks — including which exams go through which vendor, the scheduling sequence for each board, and a reference materials checklist.

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