SC Plumbing License Requirements
Yes, South Carolina Requires a License — But Which One?
South Carolina requires a license for any plumbing work that exceeds $500 on a residential project or $10,000 on a commercial project. Those thresholds include the combined value of labor, materials, and profit — not just your portion as a subcontractor. Work below those thresholds doesn't require a state contractor license, but it still needs to comply with local building codes and permit requirements.
The complication is that South Carolina splits plumbing regulation across two separate boards under the Department of Labor, Licensing and Regulation (LLR), and each board has its own requirements, application process, and filing sequence.
Two Boards, Two Tracks
The Residential Builders Commission (RBC) issues the Residential Specialty Plumbing Contractor license (RBP). This covers residential plumbing work on structures that don't exceed three floors or contain more than a single dwelling unit. Projects over $500 require this license.
The Contractor's Licensing Board (CLB) issues the Mechanical Contractor license with the Plumbing (PB) classification. This covers commercial and industrial plumbing work on projects exceeding $10,000. Holding a commercial license also authorizes you to perform residential work statewide — but the reverse isn't true. An RBP license holder cannot bid on or execute commercial work.
Residential Track Requirements (RBC)
- Experience: One year of supervised plumbing experience within the past five years, documented with notarized experience affidavits and matching W-2 or 1099 tax forms.
- Background check: Certified criminal background check from SLED (South Carolina Law Enforcement Division) for residents; equivalent statewide check from your home state for non-residents.
- Credit report: Complete credit report dated within 30 days of application submission.
- Application: Submit through the RBC's online portal with a $135 non-refundable processing fee.
- Exam eligibility: The RBC reviews your documentation first. If approved, they issue an Examination Eligibility Letter — you cannot schedule exams until you receive this letter.
- Exams: Pass both the Residential Specialty Plumbing exam and the Residential Business, Law, and Project Management exam through PSI.
- License fee: $220 after passing exams.
- Surety bond: $10,000 bond required for projects exceeding $5,000.
The critical detail: the RBC follows an "apply first, test second" sequence. You must submit your complete application and receive board approval before you can schedule any exams.
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Commercial Track Requirements (CLB)
- Experience: Two years of commercial plumbing experience within the past five years, documented through notarized Doc. 167 Work Experience Affidavits.
- Exams: Pass both the Commercial Plumbing (PB) exam and the South Carolina Business Management and Law exam through PSI. Passing threshold is 70% on each portion.
- Business entity: Register your LLC, corporation, or partnership with the South Carolina Secretary of State ($110 for an LLC).
- Financial qualification: Meet the net worth requirement for your chosen license group (Group 1 through Group 5), either through a financial statement or a surety bond under the group's bond rules. For example, Group 1 uses a $3,500 net-worth requirement or a $7,000 bond, while Group 5 uses a $200,000 net-worth requirement or a $300,000 bond.
- Insurance: General liability insurance (minimum $100,000).
- Application: Submit Doc. 165, Doc. 168 (PQP certification), Doc. 167 affidavits, PSI pass sheets, and $350 to the CLB.
The critical detail: the CLB follows a "test first, apply second" sequence — the opposite of the RBC. You register directly with PSI, pass both exams, and then submit your application. Filing an application before passing exams results in the application being returned as incomplete.
The Trade Certification Layer
Separate from both contractor licenses, South Carolina has an individual trade certification program administered by the Carolinas Associated General Contractors (CAGC) Foundation. This program issues Journeyman and Master Plumber certifications through Prov exams.
A trade certification proves technical competence but does not authorize you to independently contract for plumbing work, pull permits, or advertise services. To operate as an independent contractor, you need the trade certification (or equivalent exam passage) plus a state contractor license from either the RBC or CLB. The certified Master Plumber typically serves as the Primary Qualifying Party (PQP) for the business entity's contractor license.
Workers' Compensation
Under S.C. Code Ann. § 42-1-150, any plumbing business with four or more employees must carry workers' compensation insurance. This is an absolute statutory trigger — there's no discretion or waiver available. Operating with four or more workers and no workers' comp coverage is a criminal misdemeanor and can result in stop-work injunctions.
What Happens Without a License
The consequences of performing plumbing work above the statutory thresholds without proper credentials are severe: stop-work orders, double permit fee penalties, civil fines up to $5,000 per violation, potential criminal charges (misdemeanor), and complete loss of legal standing. An unlicensed plumber cannot enforce contracts, file mechanic's liens, or collect outstanding payments through South Carolina courts.
For the full step-by-step sequence for both tracks — including the exact filing order, documentation checklist, and local permitting requirements — the South Carolina Plumber License Guide covers the entire process.
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