The plumbing license in South Carolina works differently than most states, and the difference costs people money. There is no state journeyman or apprentice plumber license. Instead there are two separate boards, two separate credentials, and two dollar thresholds that decide which one you need.
Two boards, two thresholds
Both sit under the South Carolina Department of Labor, Licensing and Regulation (LLR).
- Residential Builders Commission issues the Residential Plumber License, required for residential plumbing work over $500. llr.sc.gov residential plumber
- Contractor Licensing Board issues the Mechanical Contractor license with the Plumbing (PB) classification, required for commercial plumbing work over $10,000. llr.sc.gov contractor licensing
Cities and counties can require their own business licensing and permits on top. Under S.C. Code 40-59-240 a locality cannot make you sit a second exam if you already passed a Commission approved one, but the local business license still applies.
Residential Plumber License
What you need:
- One year of residential plumbing experience performed within the past five years, verified with a Residential Plumber Experience Affidavit from each supervisor or employer, backed by W-2s or 1099s
- Two exams through PSI: Business Management and Law, plus the Residential Plumbing technical exam. Eligibility is good for one year, three attempts per 12 months, and three failures puts you in a 12-month wait
- A credit report dated no more than 30 days before you apply
- A $10,000 surety bond on file before you perform work over $5,000 in total construction cost. The bond names you personally as principal, not your company, and DocuSign or handwritten bonds get rejected
Fees are $135 to apply, $220 for the license, $220 to renew. The license runs two years and is due by June 30 of odd-numbered years. Late renewal costs $270 for a year past due, then reinstatement at $480. Lapse more than three years and you start over with a new application and new exams. If you do not own at least 51% of your company you also need a Certificate of Authorization, which renews at $100.
There is no net worth or financial statement requirement at this tier.
Mechanical Contractor with the PB classification
This is the commercial side. Since 2023 the threshold is total construction cost over $10,000, up from $5,000.
You designate a Primary Qualifying Party who passes the exams before the company applies. That person needs at least two years of work experience within the past five years in the classification, documented on the board Work Experience Affidavit. Two PSI exams apply: the Plumbing technical exam and the South Carolina Business Management and Law for Commercial Contractors exam. Everyone takes the business exam, even waiver applicants.
Then there is the money. Your license group sets your bid and job limit:
- Group 1: $35,000 limit, $3,500 working capital or $7,000 net worth
- Group 2: $100,000 limit, $10,000 working capital or $15,000 net worth
- Group 3: $200,000 limit, $20,000 working capital or $30,000 net worth
- Group 4: $400,000 limit, $40,000 working capital or $60,000 net worth
- Group 5: unlimited, $200,000 working capital or $300,000 net worth
You meet either working capital or net worth, not both, and a surety bond in the same amount can be substituted. Groups 1 and 2 can self prepare the statement, Groups 3 and 4 need a CPA compilation, and Group 5 needs an audited balance sheet for initial licensure. Initial licensure is $350, licenses expire October 31 of odd-numbered years, and renewal is $135 on time with escalating late fees after that. The financial statement or bond is required at every renewal, not just the first one.
Worth knowing: the board has held since 2016 that commercial natural gas piping work requires this same Mechanical Contractor license with the PB classification.
Continuing education
Neither board publishes a continuing education requirement for plumbers. The statute lets the Residential Builders Commission add one by regulation, but no CE rule currently exists in Chapter 106. Verify at renewal rather than assuming it stayed that way.
Exam waivers and reciprocity
Commercial (PB classification) exam waivers map from North Carolina (Plumbing, Class 1), Ohio (Plumbing), and Tennessee (CMC/Mechanical and CMC-A), plus a CAGC or MASC Master Plumber certification earned by exam after January 1, 1990. Waiver or grandfathered licenses from the home state do not qualify, and you still take the South Carolina business and law exam.
Residential waivers are narrower: Mississippi and North Carolina only, by exam, held at least a year, in good standing. An active South Carolina Mechanical Contractor with the PB classification held a year also works, as does a Master Plumber certification issued by exam by MASC between December 1990 and December 2025, or by CAGC after January 1, 2026.
What changed in 2026
Effective January 1, 2026, Carolinas AGC (CAGC) replaced the Municipal Association of South Carolina (MASC) as the South Carolina Mechanical Trades Certification Program provider. Old MASC certifications from December 1990 through December 2025 are still accepted, but verification letters now come from CAGC. The Residential Builders Commission also broke out a standalone Residential Plumber License application package in January 2026. Older pages still call it a Residential Specialty Contractor, Plumbing license. It is the same credential.
South Carolina plumbing license FAQ
Is there a journeyman plumber license in South Carolina? No. The state licenses at the contractor level. Journeyman style trade certification exists through CAGC but it is a certification, not a state license.
Can I do small repairs without a license? Residential plumbing work at or under $500 does not trigger the residential license. That threshold is low, so most real jobs are over it.
Do I need both licenses? Only if you work both sides. Residential remodels and service go under the Residential Plumber License, and commercial jobs over $10,000 need the Mechanical Contractor license with PB.
What does the exam cost? PSI collects the exam fees directly and LLR does not publish them, so check the PSI candidate bulletin.
Before you apply
Licensing rules change, sometimes mid-year. Confirm every requirement with the board directly before you pay a fee or schedule an exam. This page is a plain-English summary, not legal advice.
More: our plumbing license guide, the full plumbing license by state index, and how to start a plumbing business once your license is in hand.
