Charleston County’s countywide property tax rate is going up this year, and the increase lands on businesses, landlords and owners of second homes, not on owner-occupied homes.

The countywide tax rate for 2026 is 218.8 mills, up 2.7 mills from 216.1 last year, according to millage rates posted by the Charleston County Auditor’s Office this month. All of the increase comes from one line: the Charleston County School District’s operating levy, which rose to 145.2 mills from 142.5.

That is the levy homeowners don’t pay. Owners get relief from the school operating tax on their legal residence, the auditor’s office notes on its millage card. Offices, stores, warehouses, apartment buildings and vacation homes pay it in full.

County government itself held its rate steady at 37.8 mills for operations. “As far as millage, there’ll be no millage increase from Charleston County government,” County Council Chairman Joe Boykin told WCSC-TV in June.

Bills are due Jan. 15 without penalty, according to the county treasurer.

What a business pays

South Carolina taxes most commercial real estate on 6% of its market value, compared with 4% for an owner-occupied home, under state law. A property worth $1 million is assessed at $60,000, and each mill adds $60 to its bill.

That means the 2.7-mill increase adds $162 to the tax on a $1 million commercial property before credits, wherever it is in the county.

Location matters far more. A Charleston Business Report analysis of the auditor’s 2026 rates for the county’s tax districts finds the tax on a $1 million commercial property, before sales tax credits, ranges from $12,804 to $19,230. Among the districts:

  • Town of Lincolnville: 320.5 mills, $19,230
  • St. Andrew’s Public Service District, outside the city in West Ashley: 317.5 mills, $19,050
  • North Charleston Public Service District, outside the city: 313.6 mills, $18,816
  • City of North Charleston: 310.3 mills, $18,618
  • City of Charleston: 300.8 mills, $18,048
  • Town of James Island: 297.9 mills, $17,874
  • Town of Summerville, Charleston County portion: 284.8 mills, $17,088
  • Town of Mount Pleasant: 263.1 mills, $15,786
  • City of Folly Beach: 251.3 mills, $15,078
  • St. John’s Fire District, including Kiawah Island and Seabrook Island: 249.8 mills, $14,988
  • City of Isle of Palms: 240.7 mills, $14,442
  • Northern Charleston County Fire District, in areas outside city limits near Goose Creek, North Charleston and Summerville: 234.6 mills, $14,076
  • Moultrie and one James Island tax district, which pay only countywide levies: 218.8 mills, $13,128
  • Capers and Dewees islands: 213.4 mills, $12,804

The same building would owe $2,832 more in North Charleston than in Mount Pleasant, and $2,262 more in the city of Charleston.

In the city of Charleston, the school operating levy alone accounts for $8,712 of the $18,048 on a $1 million commercial property, about 48%.

Credits soften the increase

Charleston County returns part of its local option sales tax to property owners as a credit. The auditor computes it by multiplying a property’s appraised value by a factor, and the auditor’s online tax estimator applies it to property taxed at 6% as well as to owner-occupied homes.

The county factor rose to 0.0009 this year from 0.00082. On a $1 million property, that is a credit of $900, up from $820. The $80 increase offsets about half of the 2.7-mill rate increase.

Many towns add a credit of their own. Mount Pleasant’s factor rose to 0.00042 from 0.00037, and North Charleston’s to 0.00076 from 0.00073. The city of Charleston’s edged up to 0.00083. Summerville’s fell to 0.00095 from 0.00103, and Lincolnville’s to 0.00107 from 0.00121.

Homeowner versus business

The auditor’s sample calculation shows the gap. A $200,000 owner-occupied home in the city of Charleston owes $898.80 in 2026 property tax after the county and city sales tax credits and the school tax relief, plus a $154 solid waste fee.

A commercial property with the same value is assessed at 6% and gets no school tax relief. Its tax before credits would be $3,609.60. With the same county and city credits applied, as the auditor’s estimator does for property taxed at 6%, it would be $3,263.60, about 3.6 times the homeowner’s tax.

Businesses also pay tax on equipment and furniture. State law assesses most business personal property at 10.5% of its value, so $100,000 of it in the city of Charleston would carry a tax of $3,158.40 before any credits.

Special districts add more

Some fire and service districts raised their own rates on top of the school increase. Homeowners pay those levies, too.

The James Island Public Service District’s levy rose 3 mills, to 63.1, which along with the school increase lifted the combined rate by 5.7 mills in both the town of James Island and the district’s unincorporated areas. The Awendaw McClellanville Consolidated Fire District’s rose 2.8 mills, to 39.5. Isle of Palms raised its city levy 1.8 mills, to 21.9. The St. John’s Fire District rose 1 mill, and the Northern Charleston County Fire District half a mill.

For a $1 million commercial property in the town of James Island, those increases add $342 before credits, more than twice the countywide increase.

The longer view

The school operating levy has climbed from 123.7 mills in 2021 to 145.2 mills this year, auditor records show, a 17% increase. Meanwhile, the school district’s bond levy fell to 23 mills from 28, and the county government’s operating levy fell to 37.8 mills from 41.2.

Rates are not directly comparable across years because values change. In 2025, Charleston County reset values for more than 190,000 properties in a reassessment, and local governments had to adjust their rates so they would collect no more money than before, The Post and Courier reported. The countywide rate fell that year to 216.1 mills from 223.8, and the school operating levy fell to 142.5 from 145.2. This year’s levy returns it to its 2024 level.

The school district’s capital needs are on the ballot Nov. 3. Voters will decide whether to extend a 1-cent sales tax for school construction for six years, expected to raise about $1.25 billion, The Post and Courier reported Oct. 25. State law requires districts to use 10% of their sales tax share to pay down debt, lowering the debt levy on property tax bills, the newspaper reported. The money cannot pay for operations or salaries.

What the analysis doesn’t cover

The figures cover Charleston County’s tax districts only. Businesses in the Berkeley and Dorchester county parts of Charleston, North Charleston, Summerville and Goose Creek pay those counties’ rates.

The examples hold value constant, so a property whose value changed will see a different result. They also treat $1 million as the property’s taxable value. That can be lower than market value: state law caps increases at reassessment at 15% for property that hasn’t changed hands, and buyers of commercial property can apply for an exemption of up to 25% after a sale, The Post and Courier has reported. Manufacturers, utilities and properties with fee agreements in place of property taxes are taxed under different rules.

How we did this

We used the Charleston County Auditor’s 2026 millage card and millage breakdown, and the same records for 2021 through 2025, which list each tax district’s levies and sales tax credit factors. We multiplied each district’s combined millage by the assessed value of a $1 million property at the 6% commercial ratio set in S.C. Code Section 12-43-220, and applied the county and city credit factors to appraised value, as the auditor’s sample calculation does for a home and its online tax estimator does for property taxed at 6%. We also used the treasurer’s payment schedule and reporting by The Post and Courier and WCSC-TV.