Columbia SC Property Tax: 4% Rate, Act 388, and Deadlines

Columbia SC property tax is calculated by multiplying your home’s fair market value by an assessment ratio (4% if you live there as your primary residence, 6% for rentals, second homes, commercial buildings, and land) and then by the millage rate for your specific tax district. Because Columbia sits in both Richland County and Lexington County, which county your parcel falls in determines who values the property, who sends the bill, and what millage applies. Bills come out in the fall and are due January 15.

The Formula and a Worked Example

Three numbers drive every bill: fair market value, assessment ratio, and millage rate.¹ A mill equals $1 of tax per $1,000 of assessed value.

For an owner-occupied home in Richland County’s City of Columbia with a total millage of 530 mills:

Fair market value: $250,000
Assessment ratio: 4%
Assessed value: $250,000 × 0.04 = $10,000
Annual tax: $10,000 × 0.530 = $5,300

If the same house were a rental assessed at 6% and subject to school operating mills a homeowner would avoid, the bill could easily exceed $8,000. Total millage rates inside Columbia’s Richland County portion ranged roughly from 530 to 581 mills for the 2025 tax year, depending on district and school zone. Lexington County rates differ, so confirm your parcel’s county using the tax map number on your deed or either county’s online property records before you budget.

The 4% Owner-Occupied Classification

South Carolina taxes your primary residence on only 4% of its fair market value. Every other kind of real property, including rentals, vacation homes, commercial buildings, and vacant land, is assessed at 6%.² On a $250,000 house that is the difference between a $10,000 and a $15,000 taxable base, a 50% jump before millage even enters the math.

The 4% rate is not automatic. You have to apply at your county Auditor’s office and certify that the property is your legal residence. Miss the filing or move in without updating the classification and the county taxes you at 6% by default. The same applies when a rental becomes your home or a home becomes a rental: update the classification promptly or carry the wrong bill.

Act 388 Removes School Operating Mills

Once your property qualifies for the 4% ratio, Act 388 exempts it from the school operating portion of the millage rate entirely.² That is a substantial slice of the total rate and it applies automatically with the owner-occupied classification. Properties assessed at 6% receive no such exemption, which is why rental and owner-occupied bills on identical houses look so different: one owner pays a higher ratio and shoulders school operating mills the next-door neighbor avoids.

Homestead Exemption for Seniors, Disabled, and Blind Owners

South Carolina exempts the first $50,000 of fair market value from all property taxes on your primary residence if you meet one of three conditions:

You turn 65 on or before December 31 of the tax year and have lived in South Carolina for at least a year.
A state or federal agency has classified you as totally and permanently disabled. If none has, you can request an evaluation through the state’s Vocational Rehabilitation agency.
You are legally blind as defined under South Carolina law.

On a jointly owned home only one spouse needs to qualify. File with your county Auditor by July 15 of the tax year. Applications filed after July 15 but before the first penalty date in January still reduce that year’s taxes; after the penalty date, the exemption waits until the next year.³

At the 4% ratio the exemption removes $2,000 from assessed value, which is about $1,000 in annual tax savings at typical Columbia millage rates.⁴ Eligible owners who never file leave that money on the table every year.

Reassessment, the 15% Cap, and the Purchase Reset

Counties reassess all real property every five years, though a one-year extension by ordinance is allowed. Between reassessments your fair market value generally holds steady unless you build, remodel, or sell.⁵

When reassessment hits, state law caps the increase in fair market value at 15% over the five-year cycle. Two things override the cap: new construction or additions, and an assessable transfer of interest, which includes buying the property. If you purchased between reassessments, the county can reset fair market value to your purchase price regardless of the 15% limit.⁶

Buy a $300,000 house that was carried at $220,000 under the prior owner and your assessed value will catch up to the sale price. Plan the first full-year tax bill around what you paid, not what the seller was paying.

Challenging an Assessment

You have 90 days from the date the Assessor mails an assessment notice to file a written objection. You can contest the fair market value, the assessment ratio, or both. In years with no notice, you can still appeal at any time. An appeal filed before the January 15 penalty date applies to the current year; filed after, it applies to the next.⁷

Strong appeals turn on comparable sales showing nearby homes sold below the county’s figure, or on factual errors in the property record such as wrong square footage, a phantom bathroom, or a basement listed as finished when it isn’t. Arguments about the size of your tax bill, the percentage increase, or how the county spends money carry no weight: the question is whether the fair market value is accurate.

Mass appraisal values thousands of properties at once from neighborhood trends and general characteristics. A private fee appraisal from a licensed appraiser (typically $300 to $600 for a standard residential property) looks at your home in detail and can show where the mass model missed. The fee pays off when the tax savings across future years clear the cost.

Payment and the January 15 Deadline

Tax bills go out in the fall and payment is due January 15. If the county mails late, you get 30 days from mailing, whichever is later.⁸ Richland County’s Treasurer accepts online payments by Visa, MasterCard, Discover, American Express, and electronic check, with a third-party fee on card transactions, as well as in-person and mailed payments.⁹ Lexington County runs its own portal with similar options. Mailed payments are timely based on the U.S. postmark; write your tax map number on the check and verify the payment posted online afterward.

Late Penalties

Missing January 15 starts a short, steep penalty schedule:

January 16: 3% penalty added to the unpaid balance.
February 2: another 7% added.
March 17: a final 5% added.

After March 17 the Treasurer issues a tax execution and the account enters delinquent collection. One exception: if ownership changed during the year and the bill went to the prior owner, the Treasurer must waive penalties for the new owner who never received timely notice.⁸

Tax Sale and Redemption

Properties still delinquent are sold at a tax sale. The former owner then has 12 months to redeem by paying the delinquent amount plus interest on the bid, which climbs from 3% in months 1–3 to 6% in months 4–6, 9% in months 7–9, and 12% in months 10–12. Fail to redeem within 12 months and the purchaser receives a tax deed; after another 12 months, that deed becomes incontestable on procedural grounds.¹⁰

Escrow and the Federal Deduction

Most owners with a mortgage pay property tax through escrow. The lender collects a share with each monthly payment, holds it, and pays the county when the bill is due. Federal Regulation X requires an annual escrow analysis showing collections, disbursements, and any shortage or surplus.¹¹ A shortage usually raises next year’s monthly payment; a surplus of $50 or more must be refunded unless you choose to leave it. Reassessments and millage changes drive most year-to-year shifts, so a reassessed Columbia home with a higher fair market value will push the escrow portion of the mortgage up the following year.

If you itemize on your federal return, your Columbia property taxes are deductible, including the portion paid through escrow. Charges for specific services like trash collection, special assessments that add to property value such as sidewalk construction, and transfer taxes are not deductible.¹² For the 2026 tax year the base SALT cap is $40,000 (roughly $40,400 after the annual 1% adjustment), covering property taxes, state income taxes, and local taxes combined; married-filing-separately gets half. The cap phases down for modified adjusted gross income above $500,000 and bottoms at $10,000. Combined state income and property taxes above the cap bring no federal benefit.

1
South Carolina Revenue and Fiscal Affairs Office. Property Tax FAQ
2
South Carolina Legislature. South Carolina Code 12-43-220 – Classifications Shall Be Equal and Uniform
3
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
4
South Carolina Department of Revenue. Local Government Services
5
South Carolina Legislature. South Carolina Code Title 12 Chapter 37 – Assessment of Property Taxes
6
South Carolina Legislature. South Carolina Code Title 12 Chapter 37 – Assessment of Property Taxes – Section 12-37-3140
7
South Carolina Legislature. South Carolina Code 12-60-2510 – Property Tax Assessment Notices and Objections
8
South Carolina Legislature. South Carolina Code Title 12 Chapter 45 – Collection of Taxes – Section 12-45-180
9
Richland County Treasurer. Richland County Tax Information
10
South Carolina Legislature. South Carolina Code Title 12 Chapter 51 – Delinquent Tax Collector – Section 12-51-90
11
Consumer Financial Protection Bureau. 12 CFR 1024.17 – Escrow Accounts
12
Internal Revenue Service. Publication 530 – Tax Information for Homeowners