If you own a home in Marietta, Smyrna, Kennesaw, Vinings or Acworth, your Cobb County property tax bill is due October 15, 2026. The county issued 270,574 bills this year totaling $1,363,609,369, and 256,894 of them were real property bills. Whether you are a homeowner, a buyer under contract, or a seller about to close, understanding how Cobb County property tax bills work can save you real money and a lot of stress.
This guide covers the October 15 deadline, what happens if you miss it, how the tax bill works at closing, and why Cobb homeowners are in a different position than owners in many other metro counties.
Cobb County Property Tax Bills: The October 15 Deadline
According to the Cobb County Tax Commissioner, bills are mailed by August 15 and payment is due on or before October 15. Payments must be received by the due date or carry a USPS postmark showing they were mailed on time. Bills can be paid online at cobbtax.gov by e-check, debit or credit card, or digital wallet. You can also pay by phone at 1-866-535-2622, by mail to the Cobb County Tax Commissioner at PO Box 100127, Marietta, GA 30061, or in person at one of five locations. Drop boxes are available.
Processing fees can apply to some payment methods, so check the fee before you choose card payment on the final day. The office can be reached at 770-528-8600 with questions.
What happens if you pay late
The Cobb Tax Commissioner states that taxes not paid by the due date accrue a 5% penalty plus additional interest each month until paid in full. On a bill of $4,000, that 5% penalty alone is $200 before monthly interest begins. If you cannot pay the full amount, the office says it accepts partial payments and asks you to call 770-528-8600 to make payment arrangements. Do not simply wait and hope.
Escrow does not remove your responsibility
Many Cobb homeowners pay taxes through their mortgage escrow account. The Tax Commissioner is clear that when an escrow company pays, the bill still goes to both the homeowner and the mortgage company, and it remains the property owner's responsibility to make sure the bill is paid. If your lender pays on your behalf, log into your servicer account in early October and confirm the payment is scheduled. If you refinanced or bought recently, this is where bills get missed, because servicing transfers can leave a gap.
Cobb County Homeowners Are Not Under HB 581
Georgia passed HB 581, a statewide floating homestead exemption that lets local governments cap annual increases in the taxable value of a homestead. Local governments had until March 1, 2025 to opt out. On February 26, 2025, the Cobb Board of Commissioners voted 4 to 0 against adopting it, concluding that existing Cobb homestead exemptions give taxpayers better protection. The Cobb Board of Education, the City of Marietta and Marietta Board of Education, and the cities of Smyrna, Acworth, Kennesaw and Powder Springs also opted out.
What that means for you: Cobb does not use the HB 581 floating cap that many other Georgia jurisdictions chose to adopt. Your tax bill is driven by your assessed value and the millage rates set by each taxing authority, offset by the exemptions you qualify for. For a broader look at how counties compare, read our metro Atlanta property taxes by county comparison.
Buying in Marietta, Smyrna or Kennesaw: How the Tax Bill Works at Closing
The Cobb Tax Commissioner does not prorate taxes between a seller and a buyer and does not get involved in that process. Per the office, liability for taxes is established at the closing of the sale, and generally the purchaser assumes it. In practice, your closing attorney and your purchase contract determine how the year is split between the parties, and the buyer is usually the one who pays the bill when it comes due.
That timing matters in the fall. A closing in August through October can be based on the actual 2026 bill, which is cleaner. A closing earlier in the year is often prorated from the prior year figures, which can leave a gap if values or rates changed. Ask your agent and attorney three questions before closing:
- Which tax year figures are being used for the proration?
- Will the seller's homestead exemption disappear after the sale?
- Does the property sit inside a city that bills its own municipal tax, such as Marietta or Smyrna?
The second question is the one buyers miss most. A seller's bill reflects the exemptions that seller qualified for. When you buy, you start over, so budget from the current assessed value and millage rates instead of the seller's historical bill. Your monthly payment will usually be higher than the seller's tax line suggests. Our Marietta homebuyer guide walks through how that plays out near the Square.
Selling in Cobb This Fall: Avoid Surprises
If you are listing in the Northwest Metro this season, confirm that your 2026 bill is paid or will be paid at closing. An unpaid bill after October 15 carries the 5% penalty and monthly interest, and a buyer's attorney will see it at title. Pull your bill from cobbtax.gov before you list so there are no surprises.
The market gives buyers more leverage than a year ago, so clean paperwork helps you hold your price. Georgia MLS data for August 2026 shows the Atlanta Core median sales price at $400,000, active listings at 22,897 (up 3% year over year), and pending sales down 28.9% year over year. Georgia MLS leadership described it as a market where homes now compete for buyers. In that environment, a seller who presents a clear tax picture, a paid bill and an organized disclosure package looks more trustworthy and negotiates from strength. For the local picture, see our Cobb County fall 2026 housing market report.
Homestead Exemptions: Check Yours Now
Two homestead items deserve attention. First, the State of Georgia applied the Homeowner Tax Relief Grant to eligible bills this year. Second, the Tax Commissioner reminds owners that anyone who no longer qualifies for a homestead exemption must notify the office, because failure to report ineligibility may be subject to a penalty. That includes people who moved out, converted a home to a rental, or sold. If you bought a home this year, confirm that your homestead exemption is on file for the next tax year. Cobb's Tax Assessors Office handles property tax returns between January 1 and April 1, so do not wait until spring. We cover the basics in our Georgia homestead exemption guide, and seniors should read about the Cobb senior school tax exemption.
Your Cobb Property Tax Action Plan
- Find your bill at cobbtax.gov and confirm the amount and the October 15 due date.
- If you have escrow, verify with your servicer that the payment is scheduled.
- Pay by e-check to avoid card convenience fees, or mail early with a postmark.
- If you are buying, ask which tax figures are used at closing and budget from current values.
- If you are selling, make sure the 2026 bill is handled before you close.
- Review your homestead status and report any change.
Talk to The Corbin Team About Northwest Metro Atlanta
Property taxes are one line in a bigger decision. Whether you are buying in Marietta, Smyrna, Kennesaw, Vinings or Acworth, or selling a home you have owned for years, The Corbin Team will help you understand the real monthly cost, price your home with the market, and close without surprises. Call us at (678) 783-8937 and we will walk through your numbers. This article is general information, not tax advice. For questions about your specific bill, contact the Cobb County Tax Commissioner at 770-528-8600.
