Charleston County, SC — Property Tax Underwriting Guide
South Carolina · Sale-event triggered
What this means for multifamily underwriting
Charleston County is South Carolina's most active multifamily market. SC rental property (4+ units) is assessed at 6% of fair market value. Tax = FMV x 0.06 x millage. A qualifying sale resets the assessment to the purchase price.
Transaction type breakdown
South Carolina conducts countywide reassessments every 5 years. For commercial and non-owner-occupied rental property, a qualifying arm's-length sale is treated as evidence of current market value and the assessor commonly reassesses to the sale price.
Refinance does not trigger reassessment.
A qualifying ownership transfer of commercial or rental property is a reassessment trigger to current market value.
Tax appeal information
300.0 mill applied to 6% of FMV yields approximately 1.8% effective rate on market value. The high millage is by design given the low assessment ratio.
Guide review
County guidance last reviewed: June 15, 2026
Tax-rate scope: Tax-rate scope is not established as parcel-specific; confirm the parcel's taxing-authority stack.
Official sources: Charleston County Assessor
5-year cycle and 6% commercial ratio are established South Carolina law; sale-to-market-value reset for non-homestead property is common practice.
Parclio estimates are underwriting guidance, not legal or tax advice. Always verify millage rates, the seller's assessed value, and appeal deadlines with the county assessor or local counsel before relying on these numbers for a credit decision.
Run a tax reset estimate for Charleston County
Use Parclio's estimator to model the post-closing tax bill, NOI impact, DSCR change, and underwriting memo language for your next Charleston County deal.