The 4% vs 6% Assessment Ratio: South Carolina's Most Expensive Fine Print

South Carolina has some of the lowest property taxes in the country — but only if your home is assessed at the 4% owner-occupied ratio. Get classified at 6% and your bill is 50% higher. It does not happen automatically.

How South Carolina builds a property tax bill

Your tax isn't a simple percentage of value. The county multiplies your home's market value by an assessment ratio to get the "assessed value," then applies the local millagerate. The assessment ratio is the lever almost nobody from out of state understands — and it comes in two flavors:

Property typeAssessment ratioWho it applies to
Primary / legal residence4%Owner-occupied, your one legal residence
Second home / rental / investment6%Everything that isn't your legal residence

Same house, same millage — the 6% classification produces a tax bill 50% higher than the 4% one. On a $350,000 home that difference is commonly $1,200–$2,000+ per year, every year you own it.

The 4% ratio is not automatic — you must apply. When you buy, the county doesn't know the home is your legal residence until you file the legal-residence (4%) application at the county assessor's office, with proof you actually live there (SC driver's license, voter registration, vehicle registration, SC tax return). Miss it and you're billed at 6% by default. Plenty of new residents overpay for a year or more simply because no one told them to file.

Where this bites hardest: Lake Murray and snowbirds

The 6% ratio is exactly the problem for part-time and lake buyers. If a Lake Murray home is your secondhome, it's taxed at 6% — and you can only hold the 4% legal-residence rate on one property. The fix for many retirees is to make the South Carolina home the genuine legal residence (driver's license, voter registration, the works), which flips it to 4% and usually unlocks the over-65 homestead exemption too. If you'll keep a primary home in another state, budget the lake place at 6%. We walk through the lake-specific math in the Lake Murray cost-of-ownership guide.

It stacks with the over-65 homestead exemption

The 4% ratio and the $50,000 over-65 homestead exemption are two separate breaks, and you apply for each separately — both at the county. The homestead exemption removes the first $50,000 of fair market value from county, municipal and school taxes, with no income limit, for owners 65+. On a modest home, the two together can bring the bill remarkably low. Details and deadlines are in the Richland & Lexington County tax guide.

The reassessment cap

South Carolina also caps how fast your taxable value can rise: between countywide reassessments, the taxable value of your legal residence can't increase more than 15% over a five-year cycle (a sale or major improvement resets it to market). It means your bill won't balloon the way it can in fast-appreciating states — another quiet advantage of buying and holding here.

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Sources: S.C. Code Ann. §12-43-220 (assessment ratios); South Carolina Department of Revenue, Property Tax; county assessor legal-residence (4%) application guidance. General information, not tax or legal advice — confirm with your county assessor.