Cobb County property tax: assessments, appeals, and exemptions explained

Last updated 2026-07-09

How does Cobb County property tax actually work?

Cobb County sits in metro Atlanta and carries one of the highest median home values in Georgia, so the tax math matters more here than in most counties. The Cobb County Board of Tax Assessors sets the assessed value of every parcel each year. That assessed value is 40% of what the assessors think your home would sell for on the open market, a ratio Georgia law fixes under O.C.G.A. § 48-5-7 ^[1].

Take the 40% figure, subtract any exemptions you qualify for (more on those below), and you land on your net taxable value. Multiply that by the combined millage rate, divide by 1,000, and you have your bill.

For 2023, Cobb County's total unincorporated millage rate was about 28.49 mills. Rates differ if you live inside Marietta, Smyrna, Acworth, or another city, because city millage stacks on top ^[2]. A mill is $1 per $1,000 of taxable value. So a home worth $400,000 at fair market carries a net assessed value of $160,000 before exemptions, and at 28.49 mills the county portion runs roughly $4,558 before any exemption credit.

Two offices, two jobs. The Cobb County Tax Assessor's office handles valuation. The Cobb County Tax Commissioner's office handles billing and collection. If you disagree with the value, you go to the Board of Tax Assessors. If you have a billing problem, you contact the Tax Commissioner. Mixing them up costs you time you don't have.

What exemptions can lower your Cobb County property tax bill?

Georgia and Cobb County both offer exemptions that cut real money off your bill. The ones most homeowners use:

Homestead exemption. Own and occupy your Cobb County home as your primary residence as of January 1 and you qualify for a basic homestead exemption of $10,000 off assessed value for county purposes and $2,000 off for state purposes ^[3]. The deadline to apply is April 1 of the tax year. Miss it and you wait a full year.

Senior exemptions. Cobb County offers enhanced exemptions for residents 62 and older. As of the 2024 tax year, homeowners 62 and older with household income under $40,000 may qualify for a school tax exemption that strips the school millage from their bill entirely. The school portion is often the biggest slice of the total rate, so this one is worth several thousand dollars a year to those who qualify ^[3].

Disabled veteran exemption. Georgia exempts up to $109,986 of fair market value for veterans with a 100% service-connected disability rating under O.C.G.A. § 48-5-48 ^[1]. A surviving spouse can continue it.

Conservation use and agricultural exemptions. If your property qualifies as bona fide agricultural land, it may be assessed at current use value instead of market value under the Georgia Conservation Use Valuation Assessment (CUVA) program.

Every exemption starts with a one-time application filed with the Cobb County Tax Assessors office. You don't reapply each year, but you have to notify the office if your eligibility changes. Applications are due by April 1 ^[3].

What Cobb County property tax rates look like compared to nearby counties

Context matters when you're deciding whether to appeal. Here's how Cobb's 2023 total millage rates (approximate, unincorporated) stacked up against neighboring Georgia counties. These figures come from each county's published tax assessor or tax commissioner digest ^[2][9] and Census data for home values ^[11].

County	Approx. total millage (2023, unincorporated)	Median home value (2023 ACS est.)
Cobb County	28.49 mills	~$390,000
Fulton County	~38.98 mills	~$410,000
Gwinnett County	~29.97 mills	~$350,000
Cherokee County	~27.14 mills	~$370,000
Coweta County	~27.03 mills	~$305,000

Millage rates move every year as local governments set budgets, so confirm the current rate with the Cobb County Tax Commissioner before you calculate anything ^[2]. Cobb's rate sits in the middle of metro Atlanta. Fulton County's is notably higher, which is part of why fulton county property tax appeals get filed in such volume.

For neighbors elsewhere in Georgia, the gwinnett county tax assessor and cherokee county tax assessor pages walk through those counties' processes.

How to appeal property tax in Georgia: the legal framework

Georgia property tax appeals run mainly on O.C.G.A. Title 48, Chapter 5 ^[1]. Knowing the framework before you file is genuinely useful, because Georgia hands you three separate grounds, and the one you pick shapes everything after.

1. Value. You think the assessor's fair market value estimate is too high. This is the most common appeal. You need comparable sales showing homes like yours sold for less than what the assessor implies.

2. Uniformity. You think your property is assessed at a higher percentage of market value than similar nearby properties, even if the raw number looks defensible. Georgia law requires uniform assessment at 40% of fair market value across all parcels. If your neighbors are effectively taxed on 35% of value and you're taxed on 45%, that's a uniformity argument ^[1].

3. Taxability. You think the property shouldn't be taxable at all, or should sit under a different classification. Less common. It shows up when a nonprofit or government entity disputes a taxable designation.

You can raise more than one ground in the same appeal. Most homeowners focus on value, but adding a uniformity argument where the data supports it gives you a second shot if the value argument comes up short.

How to file a property tax appeal in Cobb County: step by step

The process is simpler than most people fear. Here's how it runs.

Step 1: Watch for your notice of assessment. Cobb County mails annual notices, usually in spring (often April or May). The 45-day appeal window starts the day the notice is mailed, not the day it lands in your box ^[1][6]. If you're traveling when it arrives, you can bleed days without knowing it. Set up mail forwarding or ask a neighbor to watch for it.

Step 2: Read the notice closely. It shows the assessor's fair market value estimate and the assessed (40%) value. It also prints the deadline date. Write that date down the minute you open it.

Step 3: Pull comparable sales. Gather your evidence before you file. The Cobb County tax assessor's online portal lets you search recent sales and property characteristics ^[6]. Look for homes that sold in the 12 months before January 1 of the tax year, within about a mile, with similar square footage, age, condition, and lot size. Aim for at least three comps, five if you can get them.

Step 4: File the appeal. Cobb County takes appeals online through its portal, by mail, and in person. The form asks for your parcel ID, the value you think is correct, and your grounds. You don't have to attach evidence yet, but you can ^[6].

Step 5: Attend the Board of Equalization (BOE) hearing. After you file, the Cobb County Board of Assessors either changes the value (you get a revised notice and can accept or continue) or forwards your case to the Board of Equalization. The BOE is a panel of trained citizens appointed by the Cobb County Grand Jury. Hearings are informal. Bring your comps in a clean printed packet. Explain what they show. The burden of proof shifts to the county if the assessor raised your value more than 15% in one year ^[1].

Step 6: Know your escalation path. If the BOE rules against you, you can appeal to Cobb County Superior Court within 30 days. Many people bring in an attorney at that point, though nothing requires it. For most residential appeals under $50,000 in disputed savings, Superior Court rarely pencils out unless the property is unusual.

The whole BOE process in Cobb County usually wraps within 180 days of filing, though backlogs after reassessment cycles stretch that.

What is the 45-day appeal deadline and what happens if you miss it?

The 45-day rule is hard. Georgia law at O.C.G.A. § 48-5-311 sets it: you file your appeal within 45 days of the date printed on the assessment notice ^[1]. No standard grace period. Miss it and you're locked out for that year and waiting on next year's notice.

One narrow exception exists. If you never got a notice because the assessor had a bad address on file, you can argue lack of proper service. But you have to show the county had the wrong address, more than that the mail went astray. That's a harder fight than filing on time.

Here's the practical move. If your notice arrives and the deadline is close, file a bare-bones appeal right away to preserve your rights. Strengthen the evidence package afterward. A lean appeal filed on time beats a perfect one filed too late.

Georgia also has an "amended return" process under O.C.G.A. § 48-5-299 that lets you submit your own value estimate to the assessor, separate from the appeal. It rarely moves the outcome on its own, but it's on the books.

For Fulton County neighbors researching the same thing, the deadline is identical statewide: 45 days from the notice date. The fulton county property tax appeal process runs on the same Georgia statutes, just with different BOE hearing schedules and far heavier filing volume.

How do Cobb County property tax appeal hearings work?

The Board of Equalization hearing is where most residential appeals get decided. It's less intimidating than it sounds.

You get a hearing date by mail after your appeal is accepted. Hearings run at the Cobb County government campus in Marietta. Plan for 20 to 45 minutes. The BOE panel, usually three members, sits at a table. A county assessor representative sits on the other side. You present first.

Bring a printed packet for each panel member (three copies) plus one for the assessor's rep and one for yourself. That packet should hold your subject property's assessment sheet, your comparable sales with the key data highlighted (sale price, sale date, square footage, distance from your home), and a one-page summary table. If your home has condition issues (deferred maintenance, foundation problems, flood zone), photos help.

The assessor rep defends the value. You ask questions. The panel asks questions. Then they deliberate, usually fast, and either announce a decision or mail one within a few days.

Success depends on how prepared you are and how defensible your comps are. Nobody publishes clean county-level win-rate data for Georgia BOE hearings. The closest academic work, Lincoln Institute of Land Policy research on property tax appeals broadly, suggests taxpayers who show up with comparable sales evidence win partial reductions at higher rates than those who show up empty-handed ^[7].

If you want a structured way to organize evidence before the hearing, TaxFightBack's DIY appeal kit walks you through the comparable sales analysis and hearing packet format without taking a percentage of your savings.

What happens to your tax payment while an appeal is pending?

This one trips people up. In Georgia, filing an appeal does not pause your obligation to pay the bill.

Cobb County tax bills usually mail in August with an October 15 due date ^[2]. If your appeal is still pending when the bill shows up, Georgia law under O.C.G.A. § 48-5-311(g) lets you pay 85% of the bill without penalty while the appeal is open, treating it as payment under protest ^[1]. Pay the full amount if you're unsure, because paying only 85% and then losing means you owe the rest plus interest.

Win the appeal and see your value drop, and you get a refund or credit for the overpayment. The county pays interest on refunds from successful appeals, though the rate is modest (Georgia sets it at the same rate as unpaid taxes, roughly 1% per month).

Don't ignore your tax bill because you filed an appeal. Pay at least 85% by October 15 to dodge penalties.

What evidence wins a Cobb County property tax appeal?

Comparable sales are the spine of any residential value appeal. The assessor used sales data to set your value. You use sales data to knock it down.

A strong Cobb County comp has a short list of traits: it sold within the 12 months ending January 1 of the tax year (the Georgia assessment date), it's within about a mile in a similar neighborhood, it's close on square footage (within 15 to 20% is a fair target), close on year built, and close on lot size. The further any factor drifts, the weaker the comp.

Where to find them. The Cobb County Tax Assessor's property search portal shows recent sales ^[6]. Georgia MLS (through an agent) covers more. Zillow and Redfin show sales too, but check the data against the assessor's records, because automated estimates sometimes misclassify square footage.

Condition evidence counts beyond sales. A cracked foundation, outdated electrical, a damaged roof, or other deferred maintenance that a buyer would discount deserves photos and, ideally, a contractor repair estimate. The assessor's mass appraisal system doesn't see the condition of your individual house.

Uniformity evidence (showing similar parcels assessed at lower percentages of their market value) comes from the same sales data. Find five comps that all sold for 10% less than their assessed value and your assessor's estimate is the outlier, not the market.

For how other large counties handle evidence standards, the cook county tax assessor tax bill guide covers Illinois comparable sales methodology, which shares principles with Georgia practice.

Cobb County property tax appeal freeze: is there one in Georgia?

There's no statewide property tax appeal freeze in Georgia that locks your assessed value after a successful appeal, unlike some states. Georgia does have an "assessment freeze" mechanism for homestead properties under O.C.G.A. § 48-5-2.1 that some local jurisdictions have adopted ^[1].

Cobb County uses a form of this. Once you have an active homestead exemption, the county is limited in how much it can raise your assessed value year over year. The specifics depend on the local ordinance in effect. Some Cobb taxing districts have adopted assessment increase caps for homestead properties, so even if the market jumps 20%, your taxable assessed value may be capped at a lower increase.

This is a different animal from the "property tax appeal freeze in Fulton County GA" question, which usually points at Fulton's own freeze ordinance. Fulton adopted a homestead option sales tax and assessment freeze that is broader than Cobb's. If you own in both counties or you're comparing options, check both county assessors' exemption pages directly ^[3][8].

The thing to hold onto in Cobb County: the assessment cap applies only to your homestead property, only if your homestead exemption is already on file, and it doesn't stop value increases entirely. It limits the rate of increase.

How to appeal property taxes in Georgia: the full process timeline

Here's the sequence from assessment notice to resolution, with realistic Cobb County timing.

Stage	Timing	What you do
Assessment notice mailed	Typically April-May	Review value, note deadline
45-day appeal window	Starts notice date	File appeal form with Cobb BOA
Board of Assessors review	30-90 days after filing	May resolve without hearing
Board of Equalization hearing	90-180 days after filing	Present comps and evidence
BOE decision	Day of hearing or within days	Accept or escalate
Superior Court appeal	30 days after BOE decision	Optional; attorney usually warranted
Tax bill due	October 15	Pay at least 85%
Refund if you win	After final resolution	Credited or refunded with interest

This timeline compresses or stretches. In years when Cobb County runs a mass reassessment, BOE hearing slots back up and timelines push toward the 180-day end. In lighter years, some appeals settle at the Board of Assessors level within 60 days with no hearing.

For homeowners in adjacent counties on the same path, the coweta county tax assessor and bibb county tax assessor pages cover similar Georgia timelines.

Is hiring a property tax attorney or contingency firm worth it for Cobb County?

Contingency firms usually charge 25% to 50% of the first year's tax savings they win ^[7]. On a residential appeal that saves you $800, that's $200 to $400 gone. Most residential Cobb County appeals are genuinely doable without a pro if you'll spend three to five hours pulling comps and building a simple hearing packet.

Where a professional earns the fee: commercial property appeals, parcels with complicated income-approach valuations (apartment buildings, retail centers), cases headed to Superior Court, or situations where the disputed savings top $5,000 a year. At that scale, the fee gets offset by the time and complexity involved.

For a typical single-family home in Cobb County, DIY is the rational call. The Board of Equalization process was built to be usable by owners with no legal training. Georgia law doesn't require representation. The hearing is conversational, not adversarial. Bring your printed comps, stay calm, walk through the numbers. That's the whole formula.

TaxFightBack's DIY appeal kit gives you a comparable sales worksheet, a hearing packet template, and an evidence checklist built around Georgia BOE standards, so you keep 100% of whatever reduction you win.

Frequently asked questions

How do I appeal property tax in Georgia?

File a written appeal with your county Board of Tax Assessors within 45 days of the date on your assessment notice. State your grounds (value, uniformity, or taxability) and the value you believe is correct. You don't need an attorney. If the assessors don't adjust your value, your case moves to the Board of Equalization for a hearing where you present comparable sales. The authority is O.C.G.A. § 48-5-311.

What is the deadline to appeal property taxes in Cobb County?

45 days from the date printed on your Cobb County notice of assessment, under O.C.G.A. § 48-5-311. The clock starts on the mailed date, not the date you receive it. There is no grace period. If the deadline is close when you get the notice, file immediately and add evidence afterward.

What is the Cobb County property tax millage rate?

The 2023 total millage rate for unincorporated Cobb County was about 28.49 mills. Rates vary if you live within Marietta, Smyrna, or another city, because city millage adds on top. Verify the current year's rate with the Cobb County Tax Commissioner's office before calculating your bill, since rates reset each year when local governments approve their budgets.

How is Cobb County property assessed for tax purposes?

Cobb County assesses property at 40% of its estimated fair market value, as required by O.C.G.A. § 48-5-7. The Board of Tax Assessors estimates fair market value using recent comparable sales. You multiply the 40% assessed value (minus any exemptions) by the millage rate, then divide by 1,000, to get your tax liability.

What homestead exemptions are available in Cobb County?

The basic homestead exemption reduces assessed value by $10,000 for county purposes and $2,000 for state purposes. Residents 62 and older with household income under $40,000 may qualify for a school tax exemption worth several thousand dollars annually. Disabled veterans with 100% service-connected disability may exempt up to $109,986 of fair market value. Apply by April 1 with the Cobb County Tax Assessors office.

How do I file a property tax appeal in Cobb County?

You can file online through the Cobb County Board of Tax Assessors portal, by mail, or in person at their Marietta office. You need your parcel ID, the value you believe is correct, and your grounds for appeal. Evidence isn't required at filing, but having comparable sales ready strengthens your position. File within 45 days of your assessment notice date.

Do I have to pay my tax bill while my Cobb County appeal is pending?

Yes, you still owe your bill. Georgia law allows you to pay 85% of the billed amount without penalty while an appeal is outstanding, under O.C.G.A. § 48-5-311(g). If you win a reduction, you get a refund with interest. If you pay only 85% and lose, you owe the remaining 15% plus interest. The Cobb County tax bill due date is typically October 15.

What evidence should I bring to my Board of Equalization hearing in Cobb County?

Bring a printed packet with three to five comparable sales that support a lower value: homes near yours that sold in the 12 months before January 1, with similar size, age, and condition, at lower prices than your assessed value implies. Include a summary table. If your home has condition problems, add photos and a repair estimate. Bring four copies: one for each panel member, one for the assessor rep, one for yourself.

Is there a property tax appeal freeze in Cobb County, Georgia?

There is no freeze that locks your value indefinitely after an appeal. Cobb County does have assessment increase caps for homestead properties under the Georgia homestead exemption framework, which limit how fast your assessed value can rise year over year. The freeze is not tied to filing an appeal. Check with the Cobb County Tax Assessors office for the current cap percentage applicable to your property.

How does the Cobb County appeal process compare to Fulton County?

Both counties follow identical Georgia state statutes: 45-day filing deadline, Board of Equalization hearings, same three grounds for appeal. Fulton County has a higher millage rate (roughly 38.98 mills vs Cobb's 28.49 mills) and significantly higher appeal filing volume, which means longer BOE wait times. Fulton also has a broader homestead assessment freeze ordinance than Cobb County currently offers.

Can I appeal my Cobb County property tax without a lawyer?

Yes. Georgia law doesn't require legal representation at the Board of Equalization level. The hearing is informal and designed for property owners to represent themselves. Most residential appeals hinge on comparable sales data, not legal argument. Attorneys and contingency firms typically charge 25% to 50% of first-year savings, which on a typical residential case eliminates most of the financial benefit of appealing.

How long does a Cobb County property tax appeal take to resolve?

From filing to a Board of Equalization decision typically takes 90 to 180 days in Cobb County. In heavy reassessment years, BOE hearing slots back up toward the longer end. If the Board of Assessors adjusts your value without a hearing, resolution can come in 30 to 60 days. A Superior Court appeal after a BOE decision adds at minimum several additional months.

What happens if I win my Cobb County property tax appeal?

The Board of Equalization issues a revised assessed value. The Cobb County Tax Commissioner adjusts your bill accordingly. If you already paid the original bill, you receive a refund or credit for the difference, with interest at roughly 1% per month. The reduced value typically carries into future years unless the assessor can justify an increase, though it's not permanently frozen.

How do I find comparable sales for a Cobb County property tax appeal?

Use the Cobb County Tax Assessor's online property search portal, which shows recent sales and property characteristics by neighborhood. Zillow and Redfin also display sales history, but cross-check square footage against assessor records since third-party sites sometimes have errors. Target sales from the 12 months ending January 1 of the tax year, within a mile, with similar size and age. Three to five strong comps are sufficient for most BOE hearings.

Sources

1. Georgia General Assembly, O.C.G.A. Title 48 Chapter 5 (Revenue and Taxation: Ad Valorem Taxation of Property): Georgia assesses property at 40% of fair market value; 45-day appeal deadline; three grounds for appeal; 85% payment rule; burden-of-proof shift; disabled veteran exemption amount
2. Cobb County Tax Commissioner, Property Tax Information: Cobb County millage rates, tax bill mailing schedule, October 15 due date
3. Cobb County Board of Tax Assessors, Exemptions: Homestead exemption amounts, senior exemption income threshold, April 1 application deadline
4. Cobb County Board of Tax Assessors, Property Search and Appeals Portal: Online appeal filing, property search for comparable sales, assessment notice details
5. Lincoln Institute of Land Policy, Property Tax Appeals: An Overview: Contingency firms charge 25-50% of first-year savings; taxpayers with comparable sales evidence win reductions at higher rates
6. Fulton County Board of Assessors, Homestead Exemption and Freeze: Fulton County homestead assessment freeze ordinance, distinct from Cobb County provisions
7. Cherokee County Board of Tax Assessors: Cherokee County approximate 2023 millage rate for comparison table
8. U.S. Census Bureau, American Community Survey 2023 1-Year Estimates, Median Home Values by County: Median home value estimates for Cobb, Fulton, Gwinnett, Cherokee, and Coweta counties used in comparison table