Mt. Pleasant Property Tax: Rates, Exemptions & Reassessments

Mount Pleasant property tax is billed and collected by the Charleston County Treasurer, with real estate payments due January 15 each year. What you owe depends on three numbers: your home’s fair market value, the assessment ratio for how the property is used (4% for a legal residence, 6% for a second home or rental), and the combined millage rate, which runs around 275 mills for a typical Mount Pleasant homeowner in 2025.¹

How Your Bill Is Calculated

The Charleston County Assessor’s Office estimates your property’s fair market value — what it would sell for under normal conditions. That number is multiplied by the assessment ratio to produce an “assessed value,” and the assessed value is multiplied by the millage rate to produce your tax. One mill equals one dollar of tax per $1,000 of assessed value.

For tax year 2025, the millage rates stacked onto a typical Mount Pleasant home include roughly 50.6 mills for Charleston County operations and bonds, 44.3 mills for the town of Mount Pleasant, 165.5 mills for the school district, and 14.8 mills for the East Cooper Fire District. Add them up and you’re near 275 mills.¹ The exact combination for your parcel appears on your tax bill, and the figures move each year during the budget process.

Here’s the math on a $400,000 home. At the 4% owner-occupied ratio, the assessed value is $16,000. Multiplied by 0.275, the annual bill lands near $4,400. That same home at the 6% ratio would have a $24,000 assessed value and a bill closer to $6,600.

The 4% Legal Residence Ratio and How to Claim It

South Carolina law assigns different assessment ratios by use. Your legal residence and up to five contiguous acres get the 4% ratio. Second homes, rental properties, and commercial real estate are assessed at 6%.² That difference in the ratio translates straight into a 50% difference in the tax bill on the same property value.

The 4% rate is not automatic. You file an application with the Charleston County Assessor’s Office and provide documents that tie you to the address: a South Carolina driver’s license showing the property address, vehicle registrations for every household car, and your most recent state income tax return. If the assessor decides you don’t qualify, the 6% ratio applies immediately, and you can appeal that decision.²

Agricultural tracts get the 4% ratio when owned by individuals, partnerships, or small family-held corporations with no more than ten shareholders. Non-timberland generally needs at least ten acres; timberland needs at least five. Smaller parcels can still qualify if the owner earned at least $1,000 in gross farm income in three of the past five years.²

Exemptions That Reduce Your Bill

Homestead Exemption

The Homestead Exemption removes property tax on the first $50,000 of fair market value on your primary residence. You qualify if you’re 65 or older, totally and permanently disabled, or legally blind, and have been a South Carolina resident for at least one year.³ On a home at the 4% ratio, that strips $2,000 off the assessed value, worth roughly $550 a year at current Mount Pleasant millage rates.

Applications go to the county auditor’s office, not the assessor. File in writing before July 16 to get the exemption for the current tax year. A later application generally rolls to the following year, though one filed before the first penalty date on your tax bill can still reduce that year’s taxes. Nobody applies for you; skip the application and you waive the exemption.³

Disabled Veteran Exemption

Veterans with a total, permanent, service-connected disability can claim a full property tax exemption on their home and up to five contiguous acres, plus up to two privately owned vehicles.⁴ A 2024 change by the General Assembly lets qualifying veterans claim the exemption starting the year the disability occurs, and surviving spouses can now claim it regardless of whether the veteran ever applied.

Veterans applying in 2025 can claim the exemption retroactively to 2023, provided property taxes were paid on time within two years of the application.⁴

How and When to Pay

Real estate taxes in Charleston County are due by January 15 following the tax year. The Charleston County Treasurer collects through three channels.⁵

Online, through the county’s public access portal, using Visa, MasterCard, American Express, or Discover. A surcharge applies to credit card payments and is shown before you submit.
By mail, with a check or money order sent to the treasurer’s lockbox address on your bill. Include the payment coupon so the money is credited to the right account. The postmark date counts as your payment date.
In person at a county service center, which issues an immediate printed receipt.

One restriction: if your account carries any delinquent balance, the online system blocks payment and you have to contact the Delinquent Tax Department directly.⁵

Late Payment Penalties

Missing January 15 starts an escalating penalty schedule set by state law:⁶

After January 15: 3% penalty.
After February 1: an additional 7%, bringing the total to 10%.
After March 17: an additional 5%, bringing the total to 15%. Your account also moves to the Delinquent Tax Department for collection.

The treasurer can waive penalties where clear evidence shows the payment was mailed on time but the postmark was wrong. Approval is at the treasurer’s sole discretion.

If Taxes Stay Unpaid

A delinquent notice typically goes out around April 1. Thirty days after that notice, the county can seize the property and advertise it for public auction, with real property requiring three weeks of newspaper advertisement before the sale.⁷

After a tax sale, the original owner has 12 months to redeem real property by paying all taxes, penalties, costs, and interest. Interest rises the longer you wait: 3% if you redeem within three months, 6% within six months, 9% within nine months, and 12% in the final three months.⁸ Personal property sold at a tax sale has no redemption period.

Reassessments Every Five Years

South Carolina counties reassess all real property once every five years, based on value as of December 31 of the prior year. Between cycles, your assessed value holds flat unless you change the property. The law also bars reassessment from being used to raise overall tax revenue for the county, municipality, or school board; reassessment shifts the burden among owners based on which areas gained or lost relative value, but the total collected stays the same.⁹

If you disagree with a new value, you can appeal in writing to the Charleston County Assessor, typically within 90 days of the reassessment notice. Miss that window and the value stands until the next cycle, so open the envelope when it arrives.

Improvements That Trigger a Reassessment Early

Major work can bump your assessed value outside the five-year cycle. Room additions, pools, decks, and structural rehabilitation that extends a building’s useful life all add taxable value. Cosmetic remodeling such as new countertops, cabinets, or carpeting generally does not, as long as it doesn’t add square footage. Replacing an existing roof, fixture, or appliance also won’t change your bill. The line is whether the work creates something new or maintains what was already there.

If You Have a Mortgage

Most Mount Pleasant homeowners with a mortgage never pay the treasurer directly. The servicer collects a portion of estimated annual taxes in each monthly payment and pays the January bill from escrow.

Federal rules require the servicer to analyze the escrow account each year and send you a statement within 30 days of the end of the computation year.¹⁰ If taxes went up because of a reassessment or a millage increase, the analysis will show a shortage and your monthly payment will rise; a shortage can usually be spread over the next 12 months rather than paid in a lump sum. If taxes dropped, you may get a surplus refund. That annual escrow statement is your earliest warning that your housing cost is about to change.

1
South Carolina Association of Counties. 2025 South Carolina Property Tax Rates by County
2
South Carolina Legislature. South Carolina Code 12-43-220 – Classifications and Assessment Ratios
3
South Carolina Legislature. South Carolina Code 12-37-250 – Homestead Exemption
4
South Carolina Department of Revenue. Veterans – Learn More About SC Property Tax Exemptions
5
Charleston County Government. Treasurer’s Office
6
South Carolina Legislature. South Carolina Code 12-45-180 – Penalties on Delinquent Taxes
7
South Carolina Legislature. South Carolina Code 12-51-40 – Delinquent Tax Collection
8
South Carolina Legislature. South Carolina Code 12-51-90 – Redemption of Real Property
9
Town of Mount Pleasant, SC. Charleston County to Mail Reassessment Notices
10
Consumer Financial Protection Bureau. Escrow Accounts