Key takeaways
- Assessed value is not market value — many states assess at a fraction of market value.
- Exemptions such as homestead, senior, veteran, and disability reduce taxable value.
- Appeal deadlines are short and strictly enforced, often 30 to 60 days after notice.
- Successful appeals rest on comparable sales or documented factual errors.
How your bill is calculated
Three inputs: assessed value, the assessment ratio, and the tax rate or millage. The assessor determines market value, applies the statutory assessment ratio, subtracts exemptions, and multiplies by the combined millage of every taxing authority — county, city, school district, and special districts.
Millage is expressed per $1,000 of taxable value, so 18 mills equals 1.8%. Rates vary enormously between neighboring jurisdictions, which is why two similar homes a mile apart can carry very different bills. Model yours with our property tax calculator.
Exemptions you may be missing
Homestead exemptions for owner-occupants are the most common and in some states also cap annual assessment increases. Additional exemptions exist for seniors, veterans, disabled homeowners, surviving spouses, and agricultural use.
Many are not automatic. They must be applied for, sometimes once and sometimes annually, and homeowners routinely go years without claiming exemptions they qualify for. Check your county assessor's exemption list after every purchase and after any change in circumstances.
Appealing effectively
First verify the property record card: square footage, bedroom and bath count, lot size, year built, and improvements. Factual errors are the easiest wins and are surprisingly common.
Then assemble evidence: comparable sales near the assessment date that support a lower value, photographs of condition issues, or a recent appraisal. Most jurisdictions offer an informal review before a formal board hearing, and informal review resolves many cases. Deadlines are short and jurisdictional — miss it and you wait a year.
Frequently asked questions
Will my taxes go up when I buy?
Often yes. Many jurisdictions reassess at sale price, which can substantially increase the bill over what the prior owner paid — a critical adjustment when underwriting a rental purchase.
Does a successful appeal last?
Usually for the current cycle. Some jurisdictions hold the reduced value for two or three years; others reassess annually.
Should I hire a tax appeal firm?
For residential appeals, most homeowners can handle it themselves. Contingency-fee firms are common for commercial property where the amounts justify the fee.
Sources & further reading
- International Association of Assessing Officers standards
- Lincoln Institute of Land Policy, 50-State Property Tax Comparison Study
- State property tax appeal procedures
Figures and rules change. Verify current requirements with the issuing agency or a licensed professional before acting.