If your Cobb County assessment notice arrived with a higher number than you expected, you’re not alone. In our 2025 Cobb County Residential Property Value Report, we found that only 32% of residential properties were reassessed, but those that were saw a median market value increase of 8.59%. Some homeowners faced average increases exceeding 20%.
Yet most homeowners never push back. In our Georgia Property Tax Homeowner Survey of over 850 Georgia homeowners, we found that 81% have never appealed their property tax assessment, and 51% didn’t even know they had the right to.
This guide walks through the full Cobb County appeal process, from reading your notice to attending a Board of Equalization (BOE) hearing, so you can take action before the July 20, 2026 deadline.
Key Takeaways
Cobb County homeowners have until July 20, 2026 to file a property tax appeal by mail or online.
In the most recent assessment cycle, 32% of reassessed properties saw a median market value increase of 8.59%, making appeals especially critical this year.
A successful appeal triggers Georgia’s 299(c) freeze, which locks your assessed value for 3 years.
Ownwell handles the entire process on a contingency basis: you pay nothing unless your taxes are reduced.
How Your Cobb County Property Tax Is Calculated
Before you can challenge your assessment, it helps to understand how your bill is determined.
Georgia uses an ad valorem tax system, meaning your property tax is based on your property’s fair market value (FMV). In Georgia, your assessed value equals 40% of your appraised fair market value. County and school officials then apply a millage rate, expressed per $1,000 of assessed value, to calculate your annual bill. You can find current rates on our Georgia property tax trends page.
Here’s how the math works for a typical Cobb County home:
Step | Calculation | Result |
|---|---|---|
Appraised fair market value | — | $400,000 |
Assessed value (40% of FMV) | $400,000 Ă— 0.40 | $160,000 |
Millage rate | — | 30 mills (0.030) |
Annual property tax | $160,000 Ă— 0.030 | $4,800 |
If your FMV is set too high, every number downstream is inflated. That’s exactly what an appeal is designed to correct.
Your Neighbors Might Be Paying Less...
Why Cobb County Homeowners Should Appeal in 2026
The most recent assessment data makes a strong case for filing an appeal this year. In our 2025 Cobb County Residential Property Value Report, we found a clear split in the county’s assessment practices.
The Cobb County Board of Tax Assessors chose to reassess only 32% of residential properties. The remaining 68% saw no change to their market values. But for the 73,253 properties that received new assessments, the median increase was 8.59%, and the average was 20.49%.
Entry-level homes took the biggest hit. Properties valued under $250,000 experienced a median year-over-year increase of 18.4%, even as the county’s housing market cooled and average home sales prices rose by only $20,000.
That disconnect between market reality and assessed values creates a strong foundation for appeals. If your assessment jumped while comparable sales in your neighborhood tell a different story, you likely have a case.
A successful appeal also triggers the 299(c) three-year freeze, which locks your assessed value for three consecutive years.
We’ll cover this in detail below, but the short version is that one appeal can protect you from assessment increases for three full tax years.
One important risk to know: Georgia is one of the few states where your assessed value can increase as a result of a failed or poorly prepared appeal.
If the Board of Equalization determines your property was undervalued, the county can raise your assessment. We review relevant market data before filing any appeal and may decline to file if the data suggests your current assessment is already at or below market value.
How to Appeal Your Cobb County Property Tax Assessment Step by Step
You have until July 20, 2026 to file your appeal. Here’s the process from start to finish.
1. Review Your Annual Notice of Assessment
Your notice lists your property’s current fair market value, assessed value, and any applied exemptions. This document is not a bill; it determines what you’ll eventually owe. Check every detail against what you know about your property.
2. Confirm Your Deadline
The appeal window is 45 days from the date printed on your notice. For 2026, the deadline is July 20, 2026. If you’re filing by mail, your appeal must be postmarked on or before that date. Late appeals are not accepted.
For a full breakdown of deadlines across metro Atlanta counties, see our Georgia property tax appeal deadlines guide.
3. Choose Your Appeal Route
On your appeal form, you must select one of three resolution paths:
Board of Equalization (BOE): A hearing before a three-member panel of Cobb County property owners. This is the most common route and costs nothing to file.
Hearing Officer: A certified professional appraiser hears your case. Available for non-homesteaded or commercial properties valued over $500,000.
Non-Binding Arbitration: Requires a $25 filing fee. A private arbitrator reviews the dispute.
4. File Your Appeal Online or by Mail
Online: Visit the Cobb County Board of Tax Assessors appeals page, search for your property, and click the “Appeal to the Board of Assessors” button. Upload your evidence and submit.
By mail or in person: Complete the Georgia PT-311A appeal form or write a letter stating your intent to appeal. Include your name, property address, parcel ID, your estimated property value, and your chosen appeal route. Mail or deliver to:
Cobb County Board of Tax Assessors 736 Whitlock Ave NW, Suite 200 Marietta, GA 30064
5. Receive the Board of Assessors’ Response
The Board of Tax Assessors will review your submission and may issue an amended notice with a revised value. If you accept the revised value, the appeal ends here.
6. Attend the Board of Equalization Hearing
If you disagree with the assessor’s response, your case moves to the Board of Equalization. You’ll present your evidence, the county assessor will present theirs, and the panel will issue a decision.
After processing over a million appeals, we’ve found that well-organized evidence and early filing produce the strongest outcomes at this stage.
7. Escalate to Superior Court (If Needed)
If you disagree with the BOE’s decision, you can file a notice of appeal with the Cobb County Superior Court within 30 days. For a broader look at the statewide process, see our Georgia property tax appeal guide.
What Evidence Do You Need for a Successful Appeal?
Strong evidence is the difference between a successful appeal and a wasted afternoon. Here’s what to gather before you file.
Comparable sales: Find three to five similar homes in your neighborhood that sold recently for less than your assessed value. Focus on properties with similar square footage, age, condition, and lot size that closed within the past 12 months. You can search for comparables through the Cobb County property search portal.
Property record errors: Pull your property record from the county assessor’s website. Check for incorrect square footage, bedroom or bathroom counts, lot size, or year built.
Condition documentation: Take time-stamped photographs of any structural issues, deferred maintenance, or needed repairs that reduce your property’s value.
Contractor estimates: Get written estimates for any necessary repairs. A contractor’s estimate for a $15,000 roof replacement carries more weight than a verbal claim.
Evidence Type | Strength | Example |
|---|---|---|
Comparable sales (3-5 recent) | Strong | Similar homes sold for $350K; your FMV is $420K |
Property record errors | Strong | County lists 2,400 sq ft; actual is 2,100 sq ft |
Condition photos + repair estimates | Moderate | Foundation crack with a $12,000 repair estimate |
Independent appraisal | Strong | Licensed Georgia appraiser values home at $365K |
Verbal claims without documentation | Weak | “My house needs work,” with no photos or estimates |
The 299(c) Three-Year Freeze: Why One Appeal Protects You for Three Years
Georgia offers one of the strongest post-appeal protections in the country. Under O.C.G.A. § 48-5-299(c), a successful appeal to the Board of Equalization with a reduction in value freezes your assessed value at the reduced level for three consecutive years.
During that period, your assessed value cannot increase, even if home values in your area continue to rise. The freeze can be lifted only if you file a return at a different value, file another appeal, or make substantial improvements to the property.
Here’s what that looks like in practice, assuming values increase:
Year | Without Appeal | With Successful Appeal |
|---|---|---|
Year 1 | $4,800 tax bill | $4,200 tax bill |
Year 2 | $5,040 (value increases) | $4,200 (frozen) |
Year 3 | $5,292 (value increases again) | $4,200 (frozen) |
3-Year Total | $15,132 | $12,600 |
Total Savings | — | $2,532 |
That makes Georgia one of the best states for compounding appeal savings over time.
Want to Try What Made Ownwell Famous?
Exemptions That Can Lower Your Bill Further
Appeals reduce your assessed value. Exemptions reduce the taxable portion of that value. Used together, they compound your savings.
Cobb County offers several homestead exemptions through the Cobb County Tax Commissioner’s Office. Ownwell can also help you file for exemptions. To qualify for any exemption, you must own and occupy the property as your primary residence on January 1 of the tax year.
Basic homestead exemption: $10,000 exemption in the county general and school general tax categories. Available to all qualifying homeowners.
School tax exemption (age 62+): Full exemption from school general and school bond tax categories for homeowners aged 62 or older on or before January 1.
Disability exemption: $22,000 exemption in all local property tax categories except the state. Requires disability on or before January 1 and annual net income under $12,000 (excluding disability income).
Senior exemption (age 65+, $4,000): $4,000 exemption in state, county bond, and fire district tax categories. Requires age 65+ and annual net income under $10,000 (excluding Social Security and retirement income).
Veterans’ disability exemption: Disabled veterans and surviving spouses qualify for a minimum exemption of $32,500 or the maximum amount under the index set by the U.S. Secretary of Veterans Affairs ($126,526 in 2026), whichever is greater. Any assessed value beyond the exemption amount remains taxable.
The standard application deadline is April 1. However, under HB 92 (2025), homestead exemption applications may now be submitted after April 1 for the current tax year, as long as you apply before the appeal deadline on your Notice of Assessment.
Note: Cobb County has opted out of Georgia’s floating homestead exemption under HB 581. However, the new HOME Act (Senate Bill 33), which caps annual homestead assessment increases at the rate of inflation, may provide additional protection starting in 2027.
How Ownwell Can Help
Appealing your Cobb County property tax assessment takes time, research, and familiarity with county procedures. Ownwell handles the entire process from start to finish: evidence gathering, filing, negotiations with the Board of Assessors, and representation at BOE hearings.
We operate on a contingency basis, meaning there’s no upfront cost. In Georgia, our fee is 35% of your first year’s tax savings. If your appeal doesn’t result in a reduction, you pay nothing.
If the 299(c) freeze is applied following a successful appeal, an additional $20 fee applies.
Our results speak for themselves. We boast
An 88% success rate on property tax appeals
Average annual savings of $774 for customers who saved
A 4.7-star rating across more than 3,000 Google reviews.
Before filing, we review relevant market data to make sure an appeal is worth pursuing. If we see a risk that your assessed value could increase, we may recommend against filing. That risk assessment is part of the service.
The 2026 appeal deadline is July 20, 2026. If your assessment looks too high, don’t wait.
