Property Tax Proration at Closing in Cobb County, GA
How Does Property Tax Proration Work at Closing in Cobb County, GA?
Cobb County bills a full year of property tax to whoever owned the home on January 1, and the county does not split that bill between a buyer and seller. Instead, your closing attorney prorates the tax burden between the two parties based on how many days each of you actually owned the home, using a simple per-diem formula. With 2026 Cobb County tax bills due October 15, this is exactly the line item showing up on settlement statements for anyone closing this fall.
TL;DR
- Cobb County taxes the full calendar year to whoever held title on January 1, but buyer and seller split the actual cost at closing through per-diem proration, not through the county.
- 2026 Cobb County tax bills were mailed August 15 and are due October 15. Unpaid bills after that date accrue a 5 percent penalty plus monthly interest.
- The formula is straightforward: annual tax bill divided by 365 days (366 in a leap year), multiplied by each party's days of ownership in the calendar year.
- On a $3,200 annual tax bill with a November 1 closing, the seller's share works out to roughly $2,665 for 304 days of ownership, and the buyer's share is about $535 for the remaining 61 days.
- Kennesaw and Acworth homeowners carry a higher combined millage rate than unincorporated Cobb County, so your actual proration number depends on your exact address, not just a countywide average.
If you are closing on a home in Kennesaw, Acworth, or Marietta this fall, there is a good chance you have already seen the words "tax proration" on your closing disclosure and wondered what they actually mean for your bottom line. I walk almost every client through this exact line item, because it confuses buyers and sellers more than nearly anything else on the settlement statement. Here is how it actually works, with real numbers.
How Georgia Actually Bills Your Property Taxes
Georgia counties, including Cobb, tax real property on a calendar-year basis. Whoever owns the home on January 1 is the person of record the county bills for the entire year, regardless of whether they sell the property in March, July, or November.
Cobb County mailed its 2026 tax bills on August 15, and payment is due on or before October 15, 2026. Miss that deadline and the county adds a 5 percent penalty plus interest that accrues monthly until the balance is paid in full. That deadline is only three weeks out as of this post, which is exactly why proration questions spike every September and October.
Here is the part that surprises most people: Cobb County itself does not prorate anything. The tax commissioner sends one bill for the full year to the January 1 owner and expects it paid, full stop. Splitting that cost fairly between a seller who owned the home for part of the year and a buyer who owns it for the rest is not a county function. It is a customary practice built into the GAR contract and handled entirely by your closing attorney.
The Per-Diem Formula Closing Attorneys Use
The math itself is simple, even though the explanation rarely is. Your closing attorney takes the annual tax bill, divides it by 365 days (366 in a leap year), and multiplies that daily rate by the number of days each party owns the home during the calendar year.
Annual tax bill ÷ 365 = per-diem rate
Per-diem rate × days of ownership = each party's share
Which direction the money moves depends entirely on timing.
Three Scenarios, Depending on When You Close
Closing before the fall bill is issued (roughly January through August). The seller credits the buyer at closing for the seller's share of the year, covering January 1 through the closing date. The buyer then becomes responsible for paying the full bill once it arrives in August, either directly or through a lender escrow account.
Closing after the bill is issued and already paid. If the seller already paid the full year's bill before closing, the buyer credits the seller at closing for the buyer's share of the remaining year, from the closing date through December 31.
Closing after the bill is issued but not yet paid. This is the live scenario for anyone closing between now and the end of the year. Because the Cobb County bill is outstanding, the closing attorney typically pays it in full out of the sale proceeds at the closing table, including any penalty that has already started accruing. The buyer's share is then netted out on the settlement statement, usually as a credit back to the seller.
That third scenario is worth flagging on its own: if you are a seller closing in October or November and you have not paid your tax bill yet, do not assume it simply disappears at closing. It gets paid, and it gets paid out of your proceeds.
A Worked Example: Closing November 1 in Cobb County
Numbers make this easier to follow than formulas alone. Here is an illustrative example using a $3,200 annual tax bill and a November 1, 2026 closing date. Your actual bill will depend on your home's assessed value and your specific millage rate, but the mechanics work the same way for every Cobb County closing.
| Item | Detail |
|---|---|
| Annual tax bill | $3,200 |
| Per-diem rate | $8.77 per day ($3,200 ÷ 365) |
| Seller's days of ownership | January 1 to October 31 (304 days) |
| Seller's share | Approximately $2,665 |
| Buyer's days of ownership | November 1 to December 31 (61 days) |
| Buyer's share | Approximately $535 |
Since the October 15 due date has already passed by the time this closing happens, the closing attorney pays the full $3,200 bill out of the seller's proceeds at the table. The buyer's $535 share then shows up as a credit back to the seller on the settlement statement, so the buyer is effectively reimbursing the seller for the two months of the year the buyer will actually own the home.
This is the exact kind of math I run for every client before we get anywhere near a closing table, because nobody should be surprised by a number on the settlement statement they have never seen before.
If you're selling this fall, check whether your 2026 bill has actually been paid before you get anywhere near closing. A bill sitting unpaid past October 15 is quietly accruing that 5 percent penalty every day it goes unresolved, and it comes straight out of your proceeds at the table.
If you're buying this fall, do not treat your proration credit or debit as a surprise. Ask your lender or closing attorney for the exact tax proration figure on your Closing Disclosure at least a few days before closing, not the morning of, so there are no last-minute questions about where that number came from.
Kennesaw, Acworth, and Marietta: Why Your Address Changes the Number
The proration formula stays the same everywhere in Cobb County, but the annual tax bill it is applied to does not. Homes in the cities of Kennesaw and Acworth carry municipal millage on top of the county rate, pushing their combined millage to somewhere around 39 mills, compared to roughly 30 mills for a similar home in unincorporated Cobb County. That difference alone can shift your annual bill, and therefore your proration numbers, by several hundred dollars.
Marietta is its own case entirely. The city has its own municipal millage and its own school district, Marietta City Schools, which is separate from Cobb County Schools. I was not able to confirm an exact current combined rate for Marietta in this post, and I would rather tell you that plainly than guess. If you are buying or selling in Marietta, the safest move is to pull your specific property's most recent tax bill or ask your closing attorney to confirm the exact figure before you rely on any estimate.
This is also worth separating from a different property tax question entirely: Cobb County's decision to opt out of the HB 581 floating homestead exemption freeze affects how your assessment grows after you buy, not how taxes are split at your closing table. Proration is strictly a closing-day math problem. Reassessment is a very different, ongoing one, and the two get confused constantly.
Your specific number, on either side of the transaction, depends on your home's exact address, its assessed value, and your closing date. That is exactly the kind of detail worth running with someone who knows this market before you sign anything.
Frequently Asked Questions
Does Cobb County prorate property taxes automatically?
No. Cobb County bills the full year's property tax to whoever owned the home on January 1, and the county does not split that bill between a buyer and seller. Proration happens separately, as a customary line item that your closing attorney calculates and applies to the settlement statement.
What happens if I close after October 15 and the seller has not paid the tax bill yet?
If the 2026 tax bill is still unpaid when you close, the closing attorney typically pays it in full out of the sale proceeds at the closing table, including any penalty that has already accrued. The buyer then reimburses the seller for the buyer's share of the year through a credit on the settlement statement.
How is the daily property tax rate calculated in Georgia?
Closing attorneys divide the annual tax bill by 365 days, or 366 in a leap year, to get a per-diem rate. That daily rate is then multiplied by the number of days each party owned the home during the calendar year to set the seller's and buyer's shares. You can see more Cobb County closing breakdowns on Path2Sold.com.
Do Kennesaw and Acworth homeowners pay a different tax rate than unincorporated Cobb County?
Yes. City residents pay municipal millage on top of the county rate, so a home in Kennesaw or Acworth can carry a meaningfully higher combined rate than a similar home in unincorporated Cobb County. Your exact proration number depends on your specific address, not just the county average.
Who owes property taxes if I bought my home partway through the year?
You owe taxes for every day you own the home, starting on your closing date, even though the county sends one bill for the full year to whoever held title on January 1. That is exactly what proration at closing is designed to sort out, so you are not paying for months the seller owned the property or being shorted for months you will own it.
Property tax proration is one of those closing-day details that looks small until it is a $500 or $2,000 swing on your settlement statement. Whether you are closing in Kennesaw this month or planning a sale for next spring, the only way to know your real number is to run it with someone who knows the Cobb County tax calendar cold.
Schedule a consultation with me, Robert Masoudpour, Associate Broker in Marietta, GA, and I will walk you through exactly what your closing numbers will look like before you are sitting at the table. Schedule a 15-minute consultation
