Plumbing contractor insurance in South Carolina

Two boards, two plumbing licenses in South Carolina

South Carolina splits plumbing licensing by the kind of work. Both tracks run through the Department of Labor, Licensing and Regulation (LLR).

Commercial work goes to the Contractor's Licensing Board. Mechanical contracting over $10,000 requires a mechanical contractor license with the Plumbing (PB) classification. That threshold rose from $5,000 under 2023 Act No. 69. The license comes in five groups sized by job:

• Group 1: up to $35,000 per job
• Group 2: up to $100,000
• Group 3: up to $200,000
• Group 4: up to $400,000
• Group 5: unlimited

The Contractor's Licensing Board lists the steps for each group.

Home work goes to the Residential Builders Commission. Residential plumbing over $500 needs a Residential Plumber license, earned with an exam and verified experience. A PB mechanical contractor licensed for at least a year can skip the technical exam.

Local rules can stack on top. State law says residential specialty contractors aren't exempt from county and city business license ordinances, and a county or city may require its own exam and license. It can't make you sit a second exam if you've already passed a Commission-approved one.

Check with the business license office in each town you work in.

Insurance isn't a license condition, but bonds can be. Neither track has a liability insurance minimum that we found. On the residential side, the Commission considers an applicant's workers' comp insurance as one qualification factor, with no set amount.

Two bond rules matter:

• Commercial net worth. Mechanical contractors working over $10,000 show net worth by group: $7,000 for Group 1 (or $3,500 of working capital), $15,000 for Group 2, $30,000 for Group 3, $60,000 for Group 4 and $300,000 for Group 5. You can post a surety bond for the same amount instead. Those bonds run continuously, name the State as obligee, and come on top of any project bond a contract asks for.
• Residential jobs over $5,000. A residential specialty contractor, including a residential plumber, must get a surety bond in an amount the Commission approves when a job for an individual homeowner tops $5,000.

Our license bond page explains how a surety bond works and what it costs.

South Carolina's four-employee comp line and the GC paper trail

South Carolina sets its comp line higher than most. A business with fewer than four employees regularly in service is exempt, and so is one whose total payroll was under $3,000 in the prior calendar year.

The SC Workers' Compensation Commission oversees coverage.

Sole proprietors and partners aren't covered unless they elect in by notifying the insurer.

GCs carry the risk for uninsured subs under S.C. Code 42-1-400 and 42-1-410. But 42-1-415 gives them an out. A higher-tier contractor that collects proof of the sub's comp on a Commission-approved form when the sub is hired can be relieved of that liability if the sub turns out to be uninsured. The statute applies that "regardless of the number of employees" the sub has.

So a three-person plumbing sub, legally exempt, still gets handed the form before the first rough-in. Keep a current certificate ready for every builder you work for. Existing clients can ask us for one on their current coverage and have it the same day.

Lapses have a reporting duty too. A sub whose comp lapses must tell the higher-tier contractor by certified mail within five days, or face fraud penalties.

Penalties for going without required coverage:

• $1 per employee per day, at least $10 and at most $100 a day, plus liability to injured workers (42-5-40)
• for willful refusal, a misdemeanor with a $100 to $1,000 fine, 30 days to six months in jail, or both (42-5-45)

Read our workers' comp guide for plumbers for how classes and payroll set your premium. Get a quote for your plumbing business →

Risks that shape South Carolina plumbing premiums

Subdivision volume and completed work

The Census Bureau named South Carolina the fastest-growing state in 2023, at 1.7%.

South Carolina grew 8.8% between April 2020 and July 2025, and 22.1% of its homes are from 2010 or later.

New-build work stacks up the same supply lines, water heaters and shower valves across a whole subdivision. If one batch of fittings fails, the claims arrive together. Completed operations, the part of general liability for damage that shows up after you've finished, usually has its own aggregate limit, so check that number on your declarations page.

Builders will also ask to be added as additional insureds. That takes an endorsement on your policy; a line on the certificate alone doesn't do it.

A rising tide on the coast

NOAA's Charleston gauge shows sea level rising 3.51 mm a year from 1901 to 2025, about 1.15 feet per century. Springmaid Pier near Myrtle Beach shows 3.36 mm a year since 1957.

Coastal work brings more crawlspace systems, more low sewer laterals and more yards near water. Your tools and stock should be on a floater that covers them wherever they sit, because commercial auto usually covers only gear bolted to the van.

Example scenario: A Lowcountry shop keeps its jetter trailer and a pallet of water heaters in a low yard. A spring king tide and a stalled storm push water into the lot overnight. The trailer's camera reel and the heaters' gas valves are ruined. A tools floater and coverage for stored stock respond very differently, so list both when you buy.

South Carolina markets we cover

What drives plumber insurance costs in South Carolina

There's no single South Carolina price to post. Your price depends on payroll, revenue, claims history, the work you do and the limits you choose. Four local factors move it.

Your license group. Each step up, from $7,000 of net worth for Group 1 to $300,000 for Group 5, can be met with a bond for the same amount. Bond premium is a percentage of that amount and depends on your credit, so it becomes a cost of bidding bigger work.

The four-employee line. Shops below it may not need comp by law, but most GC work will still ask for it. Plan for the premium once you sub for builders.

New-build share. Underwriters ask how much of your revenue is new construction, because completed-work claims cluster there.

Coastal location. Expect questions about where gear and vans sit overnight if you work the Lowcountry or the Grand Strand.

National figures by coverage are in the plumber insurance cost guide. Get a quote for your plumbing business →

Our South Carolina license

Plumbing Insurance Group is a brand of The Allen Thomas Group, licensed in South Carolina (License #1911336268, NPN 7642818). We quote residential plumbers and PB mechanical contractors across South Carolina, from the Upstate to the Lowcountry. See all of our state licenses.