Aiken County Property Tax: Rates, Deadlines, and Appeals

Aiken County property tax is calculated by taking your property’s fair market value, multiplying it by a statutory assessment ratio (4% for an owner-occupied home, 6% for rental or commercial property, 6% for personal vehicles), and multiplying that assessed value by the combined local millage rate. Real property bills are due January 15, and several exemptions can cut the total substantially, but only if you file for them.

How Your Bill Is Calculated

The County Assessor sets the fair market value of your real estate. South Carolina defines that as the price a willing buyer would pay a willing seller after reasonable market exposure, with neither party under pressure. The Assessor keeps a running record of deed transactions and building permits that feeds continuous reassessment.

State law then applies a fixed assessment ratio based on how the property is classified:¹

Owner-occupied homes (legal residence): 4%
Agricultural land owned by an individual or partnership: 4%
Commercial property, rental property, and second homes: 6%
Personal vehicles: 6%
Manufacturing and utility property: 10.5%
Other personal property: 10.5%

Fair market value times the ratio gives your assessed value. That assessed value is then multiplied by the millage rate to produce the tax. One mill equals one-tenth of a cent per dollar of assessed value.²

Several taxing entities each set their own millage, and your bill combines them.³ For 2025, Aiken County’s base county millage was approximately 70.34 mills, covering county operations, solid waste, Aiken Technical College, and USC Aiken. School district millage adds roughly 188 mills (operations and debt service, offset slightly by a sales tax credit). Municipal millage varies; a property inside the City of Aiken adds about another 60 mills.⁴

A Worked Example

Take a home in Aiken County with a fair market value of $200,000. As your legal residence, it’s assessed at 4%, so the assessed value is $8,000. At a combined 258 mills, the annual tax would be about $2,064. The exact figure depends on which school district and municipality the property sits in.

When Real Property Taxes Are Due

The deadline for real property is January 15, or 30 days after the notices are mailed, whichever is later. Miss it and the penalties climb quickly:⁵

After January 15: 3% penalty
After February 1: an additional 7% (10% total)
After March 17: another 5% (15% total), and the Treasurer issues a tax execution transferring the account to the delinquent tax collector

On a $2,000 bill, waiting until mid-March costs an extra $300. The postmark counts for mailed payments.

You can pay online, by mail, or in person at the Treasurer’s office. Online credit card payments carry a processing fee of roughly 2.5% charged by the payment vendor; electronic check payments carry a smaller flat fee. Check the Treasurer’s portal for current amounts.⁶

Exemptions and Discounts You Have to Apply For

Legal Residence (4% Ratio)

If a home is your primary residence, it qualifies for the 4% ratio instead of the 6% rate that applies to rental and second homes. This is not automatic. You must file an application with the County Assessor.⁷ Skipping the application leaves your home taxed at 6%, which raises the bill by 50%. It’s the most common and most expensive oversight for new homeowners in the county.

Homestead Exemption

South Carolina’s Homestead Exemption removes the first $50,000 of fair market value on a primary residence from all property taxes. You qualify if you meet any one of these: at least 65 years old, classified as totally and permanently disabled by a state or federal agency, or legally blind. You must have been a South Carolina resident for at least one year and hold title to the property.⁸ On a home assessed at 4%, that $50,000 exclusion removes taxes on $2,000 of assessed value each year.⁹

Disabled Veteran Exemption

Veterans who are permanently and totally disabled from a service-connected disability receive a complete property tax exemption on their home and up to two private passenger vehicles. You file a certificate signed by the county service officer confirming the disability. Surviving spouses of qualifying veterans may also claim it.¹⁰ The exemption starts the year the disability occurs and can be claimed retroactively for up to two prior years if taxes were paid on time in those years.¹¹

Agricultural Use Valuation

Actively farmed land can be assessed at “use value” rather than full market value. Use value reflects the productive capability of the soil, which is almost always far lower than market value. For timber, the tract must be at least five acres. For cropland or pasture, the minimum is ten acres, though smaller tracts can qualify if the owner earned at least $1,000 in gross farm income for three of the five preceding tax years.¹² Individually owned and partnership-owned qualifying agricultural land is assessed at 4%; corporate-owned agricultural land is assessed at 6%.¹

Vehicle Property Tax Works Differently

South Carolina taxes personal vehicles as property. The County Auditor values your vehicle at its fair market retail value, applies a 6% assessment ratio, and calculates the tax using the same millage rate that covers your area.¹

Unlike real estate, vehicle tax is due when you renew your registration, tied to your registration month rather than January. If you buy from a South Carolina dealer that processes the plate for you, the tax comes due 120 days after the plate is first issued. You can’t renew the registration until the tax is paid.

Appealing Your Assessment

If you think the Assessor’s valuation is too high, state law lays out the process. In a reassessment year, you have 90 days after the notice is mailed to submit a written objection to the Assessor. You can challenge the fair market value, the special use value, the assessment ratio, or the overall assessment.¹³

In years without a reassessment notice, you can still file a written objection at any time. Submitted before January 15, it applies to the current tax year. Submitted after, it applies to the following year.

Once you file, the Assessor schedules a conference. If that doesn’t resolve it, you have 30 days to file a formal written protest. From there, you can appeal to the County Board of Assessment Appeals, and then to the Administrative Law Court. Each step has a 30-day filing window.

Strong appeals rest on concrete evidence. Check the Assessor’s records for errors in your property’s physical description: wrong square footage, wrong bathroom count, features you don’t have. Comparable sales from your neighborhood that support a lower value are the most persuasive material you can bring. Arguments that the bill feels high, or complaints about county services, carry no weight.

What Happens If You Don’t Pay

Once the account transfers to the delinquent tax collector after the March deadline, additional costs accrue. If the balance stays unpaid, the county auctions the property at its annual delinquent tax sale. Aiken County typically posts sale information on September 1, with the auction later that fall.¹⁴

The original owner has 12 months from the auction to redeem the property. Redemption requires paying all delinquent taxes, assessments, penalties, and costs, plus interest owed to the winning bidder. Interest is a lump sum tied to how long you wait:

Months 1 through 3: 3% of the bid
Months 4 through 6: 6% of the bid
Months 7 through 9: 9% of the bid
Months 10 through 12: 12% of the bid

Redemption payments must be in certified funds: cash, cashier’s check, or money order. Personal checks are not accepted.¹⁵

If no one redeems within 12 months, the delinquent tax collector prepares a tax title and delivers it to the clerk of court for recording, and ownership transfers to the purchaser.¹⁶

Federal Deduction

If you itemize on your federal return, the ad valorem portion of your Aiken County property tax is deductible. Flat charges for services such as trash collection are not, even though they appear on the same bill. Special assessments for improvements that increase your property’s value, like new sidewalks or sewer lines, also don’t qualify.¹⁷ The deductible amount is also subject to the federal SALT cap, which combines state income taxes and property taxes; for the 2026 tax year that cap is $40,400 for most filers and $20,200 for those married filing separately, and it phases down for modified adjusted gross income above $505,000.¹⁸

1
South Carolina Legislature. South Carolina Code 12-43-220 – Classifications Shall Be Equal and Uniform
2
Aiken County, South Carolina. Taxpayer’s Guide
3
Aiken County South Carolina. Assessments and Taxation
4
South Carolina Association of Counties. Property Tax Rates by County, 2025
5
South Carolina Legislature. South Carolina Code 12-45-180 – Penalties on Delinquent Taxes
6
Aiken County, SC. Pay Taxes
7
Aiken County South Carolina. Frequently Asked Questions
8
South Carolina Legislature. South Carolina Code 12-37-250 – Homestead Exemption for Taxpayers Sixty-Five and Over or Those Totally and Permanently Disabled or Legally Blind
9
South Carolina Department of Revenue. Exempt Property
10
South Carolina Legislature. South Carolina Code 12-37-220 – General Exemptions From Taxes
11
South Carolina Department of Revenue. Veterans – Learn More About SC Property Tax Exemptions
12
Aiken County South Carolina. Frequently Asked Questions
13
South Carolina Legislature. South Carolina Code 12-60-2510 – Property Tax Assessment by County Assessor, Objection and Appeal
14
Aiken County, SC. Delinquent Tax Sale
15
South Carolina Legislature. South Carolina Code 12-51-90 – Redemption of Real Property Sold for Taxes
16
South Carolina Legislature. South Carolina Code 12-51-130 – Execution and Delivery of Tax Title
17
Internal Revenue Service. Real Estate Taxes, Mortgage Interest, Points, Other Property Expenses
18
NYC Comptroller. The SALT Deduction in the House Budget Bill