Georgia Commercial Property Tax: Why Your Tax Bill Can Rise Even When the Assessment Does Not

The number on your assessment notice is only one part of the bill

Commercial owners often compare this year’s tax bill with last year’s and assume the difference must come from a higher assessment. Sometimes it does. But Georgia’s system separates the value question from the rate question. That distinction matters when you are budgeting for an office building, warehouse, retail center, hotel, or mixed-use asset—and when you decide whether an appeal is the right response.

The state Department of Revenue describes Georgia property tax as an ad valorem tax, meaning it is based on value. The county board of tax assessors determines the property’s fair market value, while the governing authorities that levy taxes set the applicable millage rates. Those are related decisions, but they are not the same decision. See the state’s overview of Georgia property-tax valuation.

Start with the fair market value

Georgia’s baseline is fair market value: generally, what a knowledgeable buyer would pay and a willing seller would accept in an arm’s-length, bona fide sale. The assessor’s fair market value is not necessarily the property’s asking price, loan balance, insurance replacement cost, or the owner’s opinion of what the asset is worth.

For most taxable real and personal property, Georgia applies a 40% assessment ratio. In simplified form:

Fair market value × 40% = assessed value

A commercial property with a stated fair market value of $5 million would therefore have an assessed value of $2 million before applicable exemptions or other adjustments. The tax is then calculated against the assessed value using the millage rates for the taxing jurisdictions that apply to the parcel.

That is why a review should begin with the value shown on the notice, not with the total tax bill. If the fair market value is unsupported—for example, because the assessor used stale income data, overlooked physical problems, or selected poor comparables—that is a valuation issue. Owners who want a deeper explanation of the distinction can also review Castellan’s guide to market value versus assessed value.

Then separate the millage-rate question

A mill is one dollar of tax for every $1,000 of assessed value. Georgia’s Department of Revenue explains that county and municipal rates are set annually by the relevant governing authorities, including county commissions, city governments, and boards of education. The state does not impose a general statewide property-tax millage rate today.

The practical formula is:

Assessed value × applicable millage rate ÷ 1,000 = tax for that levy

A parcel can therefore receive a higher bill for at least three different reasons:

• The assessor increased the fair market value.
• A taxing authority adopted a higher millage rate.
• The property’s exemptions, classification, or taxable status changed.

The reverse is also possible. A higher assessment may be partly or fully offset by a lower rate. Comparing only the final bill hides which variable moved.

For current rates, do not rely on a statewide average or on last year’s budget model. The Department of Revenue maintains a property-tax millage-rate resource, but it also advises taxpayers to verify the applicable rate with the county tax commissioner. Local rates can differ by county, city, school district, and special taxing district.

What the rollback rate does—and does not—tell you

Georgia’s digest process includes a rollback concept intended to address revenue growth caused by reassessments. In broad terms, a rollback millage rate is calculated to produce the prior year’s revenue from the current digest as though reassessments had not occurred. A local authority that proposes a rate above the applicable rollback rate may have additional notice and public-hearing obligations.

That mechanism is important for public finance, but it is not a parcel-specific assessment cap. It does not mean every commercial owner’s bill will remain unchanged, and it does not establish that an individual property is correctly valued. A countywide digest can grow because of new construction, new parcels, or reassessment of existing property. A local authority can also make separate budget decisions.

The state’s property-taxpayer bill-of-rights information explains the rollback framework and the public-notice protections that accompany certain tax increases. Treat it as context for understanding the bill, not as a substitute for reviewing the property record.

Read the notice and bill as two different documents

Georgia requires the assessor to send an annual notice of current assessment for qualifying real and personal property. The notice is the document that tells you the county’s proposed or current value and explains the appeal process. The later tax bill reflects the certified digest, the applicable millage rates, and any credits, exemptions, or other adjustments.

When the documents arrive, preserve both and compare at least these fields:

1. Parcel or account number. Confirm that the notice and bill refer to the same property or personal-property account.
2. Fair market value. Check whether the county’s value changed and whether the change is explained by a sale, improvement, correction, or revaluation.
3. Assessed value. Confirm the 40% relationship unless a special statutory rule applies.
4. Taxing jurisdictions and millage rates. Identify whether the increase came from the county, city, school, or another levy.
5. Exemptions and classifications. Look for a removed exemption, a changed classification, or personal property that was added, retired, or reclassified.
6. Notice date and appeal instructions. The appeal clock generally runs from the mailing date of the assessment notice, not from the date you later open the tax bill.

The Department of Revenue’s PT-311A appeal information states that an appeal is filed with the county board of tax assessors within 45 days from the date the assessment notice was sent. Georgia’s initial appeal choices include the board of equalization, arbitration, and, for qualifying nonhomestead property over $500,000 in fair market value, a hearing officer. The choice is made when the appeal is filed, so owners should not treat the first submission as a casual placeholder.

When an appeal is—and is not—the right next step

If the value is unsupported, an appeal may be appropriate. Commercial evidence can include the property’s income and expenses, lease terms, vacancy history, operating statements, recent arms-length sales, comparable assessments, and documentation of deferred maintenance or functional obsolescence. The evidence should address the valuation date and the property’s physical and economic characteristics.

If the value is unchanged but the bill rose because of a millage-rate decision, an assessment appeal will not necessarily solve the problem. The relevant question may instead be whether the taxing authority followed the required public process or whether the bill contains a clerical, classification, exemption, or jurisdictional error. Those are different issues with different records and decision-makers.

This article describes statewide Georgia rules. County forms, electronic-filing policies, notice formats, local exemptions, and billing dates can vary. Georgia’s Department of Revenue directs owners to the county assessor for assessment questions and the county tax commissioner for billing and payment questions. Confirm local instructions before relying on a general checklist.

A practical budget rule for commercial owners

For portfolio planning, model the bill in two layers: first, a reasonable range for fair market value and assessed value; second, a current local millage-rate scenario. Do not roll forward last year’s bill by applying a single percentage to the property value. That shortcut can miss a new taxing district, a classification change, or a rate adopted after the assessment notice was issued.

If you are unsure whether the problem is value, classification, or rate, Castellan offers a free property-tax analysis. It is a starting point for organizing the record and identifying the question that deserves attention—not a promise of a reduction or a substitute for legal advice.