What is the difference between the 4% and 6% property tax rate in South Carolina?

They are assessment ratios, not the final tax rate. A home you occupy as your legal primary residence is assessed at 4% of its fair market value. Second homes, rentals, and investment properties are assessed at 6%. The county then applies its millage rate to that assessed value to calculate your bill, so the 6% classification can roughly translate to a much larger tax bill on the same house.

Do I automatically get the 4% rate when I buy my home in Charleston?

No. The 4% legal residence ratio is not automatic. You have to apply with your county assessor (Charleston, Dorchester, or Berkeley) and provide documentation that the home is your legal primary residence. If you never file, the property stays at the 6% rate and you overpay every single year.

What is the South Carolina Homestead Exemption?

It is an additional break for owner-occupants who are 65 or older, totally and permanently disabled, or legally blind, and who have been South Carolina residents for at least a year. It exempts the first $50,000 of your home's fair market value from property tax, on top of the 4% legal residence ratio. You apply through your county auditor.

South Carolina's 4% vs 6% Property Tax: A Charleston Buyer's Guide

Here is a scenario that catches Charleston buyers off guard every month. You find a house, you pull up the listing, and the property tax number looks reasonable. You buy it. The next tax bill shows up and it is hundreds or even thousands of dollars higher than you expected. Nobody lied to you. You just ran into South Carolina’s 4% versus 6% system, and probably forgot to file one form.

Let me walk you through it so you are not that buyer.

The short version

South Carolina taxes real estate using an “assessment ratio.” It is not the tax rate itself. It is the slice of your home’s value that actually gets taxed. For owner-occupied, primary residences the assessment ratio is 4%. For non-primary residences, the rate is 6%.

That gap sounds small. It is not. The 6% ratio means half again as much of your home’s value is exposed to the millage rate, which on a typical Charleston-area home can mean a tax bill that is dramatically larger for the exact same property.

How the math actually works

The formula has three parts:

Fair Market Value × Assessment Ratio × Millage Rate = your tax bill

Say you buy a $400,000 home in Charleston County and it is your primary residence. At the 4% ratio, your assessed value is $16,000. The same home as a second home or rental, at 6%, has an assessed value of $24,000. The county then multiplies whichever number applies by the local millage rate for your specific tax district to get the bill.

Millage varies a lot depending on whether you are in the city, in a town like Mount Pleasant or Summerville, or in an unincorporated part of the county, so I am not going to pretend there is one number that fits everyone. Charleston County publishes an online tax estimator where you can plug in an address and see the real figure for that district. Use it before you make an offer, not after.

The catch nobody mentions at the closing table

The 4% rate is not automatic. This is the part that costs people real money.

The 4% rate applies only if you file the proper paperwork with your county’s assessor’s office. If you buy a home, move in, and never file the legal residence application, the county keeps taxing you at 6% as though it were an investment property. You can live there for years overpaying and never realize it.

So the single most important thing you do after closing on your Charleston-area home is not picking paint colors. It is filing the legal residence application with the right county assessor. We have three counties in the metro: Charleston, Dorchester, and Berkeley. Each runs its own assessor’s office, and each has its own form and deadline. File promptly after your deed is recorded.

The “Zillow trap”

When you look at a listing’s estimated property tax, that number often reflects how the current owner is taxed, not how you will be taxed. If the seller used it as a second home at 6%, the listed tax might be higher than what you will pay as a primary resident at 4%. If the seller lived there at 4% and you are buying it as a rental, the reverse is true and the real bill will be higher than the listing suggests.

Either way, never take the listing’s tax figure at face value. Run your own numbers for your own intended use.

A bonus break for some owners

If you are 65 or older, totally and permanently disabled, or legally blind, and you have been a South Carolina resident for at least a year, you may also qualify for the Homestead Exemption. It gives the property owner an exemption on the first $50,000.00 in Fair Market Value of the property. That stacks on top of the 4% ratio, and for a qualifying retiree on a moderately priced home it can pull the annual bill down to a genuinely small number. You apply for it through your county auditor.

Do not try to game it

I will be blunt here because I have seen it go badly. Claiming the 4% legal residence rate on a home that is not actually your primary residence is not a clever loophole. Counties audit for exactly this. Upon notification, the owners are required to pay the taxes due at the 6% assessment ratio. The taxes paid, previously, at the 4% assessment ratio are forfeited, plus interest, as the penalty. Dorchester County, for one, uses third-party data tools to flag owners claiming the rate on more than one property. It is not worth it.

What to do after you close

Three things, in order:

File your legal residence application with the correct county assessor as soon as your deed records.
Run the county tax estimator for your address so your escrow and budget reflect reality.
Check whether you qualify for the Homestead Exemption if you are 65+, disabled, or blind, and apply through the auditor.

This is general information, not tax or legal advice, and the counties each have their own deadlines and quirks, so confirm the specifics with your closing attorney and the assessor’s office. If you want help modeling what a specific home would actually cost you at 4% versus 6% before you write an offer, that is exactly the kind of thing I walk buyers through. Reach out and we will run the real numbers for the homes you are considering.