Eight checks, all of which you can make yourself before signing anything.
South Carolina licenses plumbing in two places, and which one applies depends on what the job costs. A residential plumber is licensed by the Residential Builders Commission after an examination; above ten thousand dollars of construction the work belongs to a mechanical contractor licensed by the Contractor’s Licensing Board with the plumbing subclassification.
The search is at verify.llronline.com. Worth knowing: verify.llr.sc.gov, which a great many articles print, has no DNS record at all — if a lookup link has failed for you before, that is probably why. Check the licence is active, that its class covers the value of your job, and that the name on it matches the name going on the contract.
A trade permit is pulled by the licensed contractor performing that trade, in that contractor’s own name, and a building official is required to refuse to issue one unless the applicant produces evidence of licensure or an exemption.
On our work the plumbing subcontractor pulls their own. Any answer along the lines of "you can pull it as the homeowner" is a reason to keep looking, because it moves the liability to you.
A PDF forwarded by email proves nothing about whether the policy is still in force. Ask for it to be sent by the agent.
Plumbing is water-damage work by nature, so ask specifically what the general liability limit is and whether workers’ compensation covers everyone who will be on your property, subcontractors included.
On a plumbing job the scope has to say which fixtures, which pipe material, how much of the existing run is being replaced and where the work stops.
A number with no scope behind it cannot be compared with another number, and the scope is where a low bid quietly excludes the part of the job that turns out to be expensive.
This is the plumbing-specific version of "what if you find something". Cast iron drainage and galvanised supply frequently fail next to a new fitting, because the repair puts a rigid new joint into tired pipe.
Every honest answer involves stopping, showing you, and pricing it before continuing. Ask it precisely because nobody rehearses it.
The rating matters less than how the business behaved when something went wrong. A calm, specific reply to a bad review tells you more than fifty five-star ratings.
For plumbing, look particularly for how they handled a repair that failed and a bill that grew.
Ask whether they have been under a Charleston house before. The failures here are local: a closed system from the dual check valve CWS has fitted to every residential service since 1985, crawl space runs in a high water table, and cast iron in the older parts of the peninsula and West Ashley.
On a sewer lateral, ask about the Charleston Water System grant before agreeing to anything. It reimburses part of the cost from a $50,000-a-year fund, requires a licensed plumber, and a contractor who has not heard of it is telling you something about how much local work they do.
Southeastern Renovation is a general contractor, SC licence CLG.127339, and you can check that at the link above rather than taking our word for it. That licence is not a plumbing licence and we do not pretend otherwise: plumbing is performed by a licensed plumbing subcontractor who pulls the plumbing permit in their own name. Scopes are written before prices. We are not going to tell you we are the best plumber in Charleston, because that is not a claim anybody can check — the eight above are.