You opened your tax bill to find it significantly higher than last year's. You haven't renovated, you haven't expanded, and yet your annual tax burden jumped by hundreds or even thousands of dollars. You're not alone.
Nearly three-quarters (74%) of American homeowners worry about significant property tax increases, yet only 22% have ever appealed. Of those who haven't, more than half didn't even know they could.
Your tax bill can rise for several specific, identifiable reasons, and most of them are fixable. The sections below walk through each cause and the steps you can take to lower your bill.
Key Takeaways
Your tax bill increases when your home's assessed value rises, local tax rates change, or an exemption expires.
Rising home prices in your area can trigger a reassessment even if you haven't changed anything about your property.
Errors on your assessment are more common than most homeowners realize, and they compound year over year.
You have the right to protest (TX), grieve (NY), or appeal your assessment in every state; Ownwell can help in select states.
How Property Taxes Are Calculated
Your annual tax bill comes down to a simple formula:
Taxable Value x Tax Rate = Annual Tax Bill
Each piece of that equation matters. Your county assessor estimates your home's market value, then subtracts any exemptions you qualify for to arrive at the assessed (taxable) value. That number is not the same as what your home would sell for; it's the assessor's estimate, and it can be wrong.
The tax rate, sometimes called the millage rate, is set by every local taxing authority that covers your property. School districts, counties, cities, and special districts each stack their own rates on top of one another.
A change in either your assessed value or your tax rate (or both) can increase your bill. After processing over a million appeals, Ownwell has found that most homeowners don't realize their bills are driven by two separate factors.
Understanding which one changed tells you exactly what to do about it. You can appeal your assessed value. You cannot appeal the tax rate.
How Much Are You Over Paying?
5 Reasons Your Property Taxes Went Up
1. Your Home's Assessed Value Increased
This is the most common reason your tax bill jumped. County assessors periodically reassess property values based on comparable sales in your area.
If home prices in your neighborhood rose, your assessed value likely increased, even if you haven't changed anything about your property. In Texas alone, the median home price jumped from $259,990 to $335,000 between 2020 and 2023.
Reassessment frequency varies by state. Texas and Georgia reassess annually; other states reassess every two to five years.
Your assessment can increase even in a flat market if prior years were undervalued.
Check Texas property tax trends or Georgia property tax trends for local market data showing how values in your county have shifted.
2. Local Tax Rates Went Up
Even if your assessed value stayed flat, your bill can rise because a taxing authority raised its rate. Multiple entities set rates that stack on top of each other:
School districts: Often the largest portion of your tax bill. Districts propose bond measures and tax rate increases for a public vote.
Counties: Fund roads, law enforcement, courts, and county services. County commissioners or boards set the rate, typically after public budget hearings.
Cities and municipalities: Fund police, fire, parks, and infrastructure. City councils approve budgets and can raise rates, sometimes requiring voter approval for increases above a certain threshold.
Special districts: Water, hospital, emergency services, and municipal utility districts each levy their own rate. These often fly under the radar because voters may not realize they're separate taxing entities.
When any of these bodies increases spending through bond elections, infrastructure projects, or budget shortfalls, your combined rate climbs. The Tax Policy Center provides a detailed breakdown of how these rates are set. Most rate changes follow a public hearing and vote, so attending local budget meetings gives you a voice before the increase takes effect.
This is the one factor you cannot appeal. You can only challenge your assessed value, not the rate itself.
3. You Made Improvements or Additions
Permitted improvements trigger reassessments because they add permanent value to your property:
Room additions and new square footage: The most common reassessment trigger.
In-ground pools, garages, or detached structures: Permanent structures increase assessed value.
Major kitchen or bathroom renovations: Structural changes requiring permits signal capital improvements to the assessor.
The increase should reflect the added market value of the improvement, not the full construction cost. If the bump seems disproportionate, the assessment may be worth challenging. Learn more about what home improvements increase property taxes.
4. An Exemption Expired or Was Never Applied
Exemptions reduce your taxable value by thousands of dollars. Common ones include:
Homestead exemption: Lowers the taxable value on your primary residence. Does not transfer upon sale of the property.
Senior exemption (65+): Additional reduction, sometimes with a tax ceiling that freezes your bill.
Disability and veteran exemptions: Range from partial reductions to full exemptions depending on the state and disability rating.
If you recently purchased your home, the previous owner's exemption likely did not transfer. You may need to file a new application.
In Texas, Michigan, Illinois, and New York, Ownwell can help you file retroactive exemption applications covering 1 to 3 prior years of missed savings. Visit property tax exemptions to see what you may qualify for.
5. There's an Error on Your Assessment
Assessors manage thousands of properties, and mistakes happen more often than most homeowners realize. Common errors include:
Incorrect square footage or lot size
Wrong bedroom or bathroom count
Misclassified property type (e.g., residential listed as commercial)
Outdated condition ratings that don't reflect damage or deferred maintenance
The real cost of an error is that it compounds. An uncorrected mistake inflates your taxes every year until someone catches it.
Ownwell reviews assessment data as part of every appeal, catching these errors during the process, often before the homeowner even knows they exist.
What a Property Tax Increase Actually Costs You (Worked Example)
Numbers make this real. Here's what a reassessment looks like in dollars for a homeowner in Texas.
Scenario: Your home was assessed at $350,000 last year. This year, the county reassessed it at $410,000. Your combined tax rate is 2.10%.
| Before | After |
|---|---|---|
Assessed Value: | $350,000 | $410,000 |
Tax Rate: | 2.10% | 2.10% |
Annual Tax Bill: | $7,350 | $8,610 |
Increase: | -- | $1,260/year |
That $1,260 increase hits your budget immediately, but the real damage is what happens next...
If the over-assessment stands, you overpay not just this year but every subsequent year until the value is corrected.
Ownwell's analysis of 17 Texas counties found that homeowners who skipped their 2025 protest left $1.2 billion in potential savings on the table in a single year. Over-assessments compound, and the gap widens every year you don't act.
Now, here's what happens after a successful appeal:
| Over-Assessed | After Appeal |
|---|---|---|
Assessed Value: | $410,000 | $370,000 |
Annual Tax Bill: | $8,610 | $7,770 |
Annual Savings: | -- | $840/year |
That $840 per year adds up. Over five years, you save $4,200, and that's before accounting for the compounding effect of a lower base value in future reassessments. The earlier you act, the more you keep.
What You Can Do About a Property Tax Increase
Appeal Your Assessment
You have the legal right to challenge your assessed value. The process is called a "protest" in Texas, a "grievance" in New York, and an "appeal" in most other states. Filing deadlines vary, typically 30 to 90 days after you receive your assessment notice, so check your notice as soon as it arrives.
The odds are in your favor. Between 60% and 80% of Texas property tax protests result in a reduction. Despite those odds, only 32% of homeowners across 17 major Texas counties protested in 2025.
The cost of inaction is staggering. Across the Texas counties studied, homeowners who didn't protest left $3.3 billion in potential savings on the table from 2023 to 2025. And Ownwell's National Homeowner Survey found that 53% of homeowners who have never appealed didn't even know they had the right to do so.
Ownwell manages the entire property tax appeals process, from market analysis and evidence preparation to filing, negotiation, and hearings, so you don't have to navigate it alone. After processing over a million appeals,
Ownwell has an 88% success rate and saves customers an average of $774 per year.
Check for Missing Exemptions
Homestead, senior, disability, and veteran exemptions can reduce your taxable value by thousands of dollars each year. If you bought your home recently, the previous owner's exemption likely did not transfer with the property. You may need to file a new application.
In Texas, Michigan, Illinois, and New York, you can file retroactive applications to recover one to three years of missed savings. Ownwell's exemption service handles discovery, filing, and ongoing monitoring so you never miss a deadline again.
Unsure Which Exemptions You Qualify For?
Review Your Assessment for Errors
Pull your property record from the county assessor's website and check the basics: square footage, lot size, bedroom and bathroom count, property classification, and recent comparable sales used to determine your value.
If any data point is wrong, you have strong grounds for an appeal. Ownwell's analysis catches these errors automatically during the appeal process. If you'd rather skip the research, filing through Ownwell covers the error review for you.
Ownwell's Appeal and Exemptions Services
Every reason your tax bill increased, whether a rising assessment, a missed exemption, or an assessor's error, is something Ownwell is built to address.
End-to-end appeals: We handle market analysis, evidence preparation, filing, negotiation, and hearings, so you don't need to take time off work or learn the appeals process yourself.
Data-driven case building: Each appeal is backed by comparative market analysis using real-time data, local expertise, and AI to build the strongest possible case for your property.
No upfront cost: Ownwell works on a contingency basis. If your appeal doesn't save you money, you pay nothing. See Ownwell's pricing for details.
Proven results: We've processed over one million appeals, achieving an 88% success rate and saving customers an average of $774 per year. Our service holds a 4.7 rating across 3,000+ Google reviews.
Exemption filing: We also identify and file for exemptions you may be missing, including retroactive applications in states that allow them.
Multi-state coverage: We operate in Texas, Florida, Georgia, Illinois, New York, California, Washington, Pennsylvania, Colorado, and other states. Visit your state's page, like Texas property tax trends, for local data.
Risk disclosure: In Washington and Georgia, a failed or poorly executed appeal can result in an increased taxable value. Ownwell reviews your data before filing to ensure the appeal is in your best interest.
Frequently Asked Questions
How Often Are Property Taxes Reassessed?
It depends on your state. Texas and Georgia reassess annually, while states like New York and Illinois may reassess every two to five years. Check your county assessor's website or visit Texas property tax trends or your state's page for local details.
Can I Appeal My Property Tax Assessment?
Yes. Every state gives homeowners the right to challenge their assessed value. In Texas, it's called a "protest"; in New York, a "grievance"; and in most other states, an "appeal." Ownwell handles the entire process on a contingency basis — you pay nothing unless your taxes are reduced.
Learn more in the property tax appeal guide.
How Much Can Property Taxes Increase in One Year?
There's no universal cap. Some states limit annual increases (California's Prop 13 caps assessed value growth at 2% per year for existing owners), but many states have no ceiling. A reassessment of the current market value after years of low growth can result in a double-digit percentage increase.
What Happens if I Don't Appeal?
You continue paying based on the current assessed value, which becomes the baseline for future years, compounding the overpayment. Across 17 Texas counties, homeowners who didn't protest left $3.3 billion in potential savings unclaimed from 2023 to 2025.
Does Appealing My Property Taxes Cost Money?
With Ownwell, there's no upfront cost. You pay a contingency fee only if your appeal succeeds and your taxes are reduced. If Ownwell doesn't save you money, you owe nothing.
