A property tax appeal is only as strong as the evidence behind it. The county assessor won't lower your assessment because you think your taxes are too high—you need to prove your property is worth less than what's on the books. This guide covers exactly what evidence and documents you need, where to get them, and how to put them together.
Evidence Overview: What Matters Most
Not all evidence carries equal weight. The assessor is looking for objective, verifiable proof that your property's market value is lower than the assessed value. Here's how different types of evidence rank:
Evidence Priority Ranking
- Comparable sales — Similar homes that sold for less than your assessed value. This is the single most persuasive evidence.
- Property record errors — Incorrect square footage, room counts, or features in the assessor's records. Easy to prove and hard to argue against.
- Condition documentation — Photos and contractor estimates for deferred maintenance, foundation problems, or other issues reducing value.
- Professional appraisal — A recent appraisal from a licensed appraiser showing a lower value. Strong but not required.
- External factor documentation — Evidence of traffic noise, flood zones, commercial neighbors, or other location-based negatives.
A strong appeal typically combines at least two types of evidence. Comparable sales are the foundation, and everything else strengthens the case.
Comparable Sales (The Most Important Evidence)
Critical Comparable Sales Data
The cornerstone of any successful property tax appeal
Comparable sales—or "comps"—are records of similar homes that sold recently for less than your assessed value. If you can show that homes like yours are selling for less than the county thinks your home is worth, you have a strong case.
What You Need for Each Comparable
- Official Sales Record The deed or sales record showing the actual sale price, date, buyer, and seller. Get this from the county assessor's website or register of deeds.
- Property Details Square footage, bedrooms, bathrooms, year built, lot size, and features for each comparable. Pull this from the assessor's records.
- Comparison Notes A brief explanation of how each comp compares to your property—why it's similar and how the sale price supports a lower assessment for your home.
What Makes a Strong Comparable
- Similar size: Within 10-20% of your home's square footage
- Similar age: Built within 10-15 years of your home
- Same neighborhood: Ideally within 1 mile and in the same market area
- Recent sale: Sold within the past 6-12 months
- Arm's-length transaction: Normal market sale between unrelated parties
- Similar features: Comparable bedrooms, bathrooms, garage, lot size
Where to Find Comparable Sales
- County assessor's website (padctn.org for Davidson County, williamsoncounty-tn.gov for Williamson County)
- Tennessee Register of Deeds for official deed records
- MLS data through a licensed real estate agent
- Tennessee Comptroller real estate transfer records
Avoid These Common Comp Mistakes
Don't use foreclosure sales, short sales, family transfers, or properties vastly different from yours. The assessor will reject these immediately. Also avoid Zillow estimates—they are not official records and carry no weight in an appeal.
Your Property Record Card
Critical Property Record Card & Error Documentation
Errors in your property record directly inflate your assessment
Your property record card is what the assessor uses to determine your home's value. If it contains errors, you're being taxed on a property that doesn't match reality. Getting your record card and checking it for accuracy is one of the most important steps in any appeal.
Documents You Need
- Your Property Record Card Download from the county assessor's website. Shows all property details the assessor has on file: square footage, lot size, year built, rooms, features, and condition.
- Error Documentation For each error you find, provide proof: measurements, photos, floor plans from your home purchase, or a recent appraisal showing correct figures.
- Your Tax Notice Your most recent property tax notice showing the current appraised value, assessed value, and tax amount.
Common Errors to Look For
- Wrong total square footage (heated/living area)
- Incorrect number of bedrooms or bathrooms
- Features listed that don't exist (pool, finished basement, fireplace)
- Wrong year built
- Incorrect lot size or acreage
- Garage or outbuilding that was removed or doesn't exist
- Wrong exterior material or roof type
- Condition rating that doesn't match reality
Pro Tip: Measure Your Home
Square footage is the most common error and has the biggest impact on assessed value. If you have a recent appraisal, check its square footage against the assessor's record. Even a 100 sq ft discrepancy can mean hundreds of dollars in over-taxation per year.
Condition Documentation
Important Photos, Repair Estimates & Inspection Reports
Document anything that reduces your home's market value
If your home has condition issues that the assessor's mass appraisal didn't account for, you need to document them clearly. The assessor can't see inside your house—you need to show them.
Documents and Evidence to Gather
- Dated Photographs Clear photos of every condition issue: foundation cracks, roof damage, water stains, outdated kitchens/bathrooms, damaged flooring, HVAC problems. Include date stamps.
- Written Repair Estimates Get quotes from licensed contractors for major issues. A written estimate on letterhead showing the cost to fix foundation, roof, HVAC, or plumbing problems adds significant weight.
- Home Inspection Reports If you have a recent home inspection (from a purchase or for insurance), include the relevant sections documenting problems.
- Insurance Claims Records If you've filed insurance claims for damage (hail, water, fire), include records showing the extent and nature of the damage.
What Issues to Document
- Foundation cracks or settling
- Roof damage or age (nearing end of life)
- Outdated electrical, plumbing, or HVAC systems
- Water damage or mold
- Deferred maintenance (peeling paint, rotting wood, broken fixtures)
- Functional obsolescence (outdated layout, small rooms, poor flow)
- Structural issues (sagging floors, cracked walls)
Negative External Factors
Helpful Location-Based Evidence
Factors the mass appraisal may have missed
Mass appraisals value properties based on neighborhood averages. But individual properties can have location-specific issues that reduce their value compared to nearby homes. If your property is affected by any of these, document them:
- Photos of External Issues Photographs showing proximity to commercial properties, power lines, railroad tracks, busy roads, or other negative factors.
- FEMA Flood Zone Maps If your property is in a designated flood zone, include the FEMA map showing the classification. Flood zone designation reduces market value and increases insurance costs.
- Environmental Reports Documentation of environmental concerns: contaminated soil, nearby industrial activity, airport noise zones, or other environmental impacts.
Supporting Documents
Helpful Additional Documents That Strengthen Your Case
Not required, but valuable when available
- Recent Professional Appraisal If you have an appraisal from a purchase, refinance, or estate matter showing a value lower than your assessment, include it. Don't pay for one just for the appeal unless you have high-value property.
- Recent Purchase Price Documentation If you bought your home recently for less than the assessed value, your purchase price is strong evidence of market value. Include the closing statement (HUD-1 or Closing Disclosure).
- Listing History If your home was listed for sale and didn't sell, or sold for less than asking, this demonstrates market value. Include MLS listing records showing days on market and price reductions.
- Building Permits and Surveys If you have survey documents or building permits that confirm your property's actual dimensions, lot boundaries, or the absence of features the assessor has on record.
What Works vs. What Doesn't
Understanding what the assessor accepts—and what they reject—saves you time and improves your chances:
Strong Evidence
- Official sales records from county assessor or register of deeds
- MLS sales data from a licensed agent
- Your actual property record card with errors highlighted
- Dated photos of condition issues
- Written estimates on contractor letterhead
- Licensed appraiser's report
- FEMA flood maps
- Closing statement showing purchase price
- Clear comparison chart of your property vs. comps
Weak or Rejected Evidence
- Zillow estimates or Zestimates
- Redfin, Realtor.com, or other algorithmic estimates
- Opinions from friends or neighbors
- Foreclosure or short sale prices
- Family member or non-arm's-length sales
- Comps from different neighborhoods or property types
- Emotional arguments ("my taxes are too high")
- Complaints about tax rates (assessor sets value, not rates)
- Outdated sales data (more than 12-18 months old)
How to Organize Your Evidence
A well-organized evidence package stands out. The assessor reviews hundreds or thousands of appeals. A clear, professional submission gets better results than a pile of loose documents.
Evidence Package Structure
Pro Tip: Lead with Your Strongest Evidence
Put your best comparable sales right after the cover letter. If the assessor is convinced by page 2, you've won. Don't bury strong evidence at the end of a long packet. Number your pages and include a table of contents for submissions longer than 10 pages.
Keep Copies of Everything
Always keep a complete copy of everything you submit. If you need to escalate to a formal hearing, you'll need your original evidence. If you file online, save confirmation receipts. If you file in person, get a stamped receipt.
Frequently Asked Questions
What evidence is needed to support a property tax appeal?
The most important evidence is comparable sales—3-5 similar homes that sold recently for less than your assessed value. You should also include your property record card with any errors highlighted, photos and repair estimates for condition issues, and documentation of negative external factors like flood zones or traffic noise. A well-organized evidence package with a clear summary significantly improves your chances.
What documents are needed for a property tax appeal?
Key documents include: your property record card from the assessor's office, comparable sales records (official sales data, not online estimates), photos of property condition issues, contractor repair estimates for major problems, any recent professional appraisals, FEMA flood zone maps if applicable, and a cover letter summarizing your case. Organize all documents into a clear, professional package.
Can I use Zillow estimates as evidence in a property tax appeal?
No. Zillow Zestimates and similar online estimates are algorithmic guesses, not official records. Assessors will reject them. Use actual sales records from your county assessor's website, official deed records, or MLS data instead.
How many comparable sales do I need for a property tax appeal?
Aim for 3-5 strong comparable sales. Quality matters more than quantity. Three excellent comps that closely match your property in size, age, location, and features are better than ten weak ones that the assessor will reject.
Do I need a professional appraisal to appeal my property taxes?
No, a professional appraisal is not required. While a recent appraisal showing a lower value can strengthen your case, comparable sales and property record corrections are usually sufficient. If you already have an appraisal from a purchase or refinance, include it. But don't pay for one just for the appeal unless your property value is high enough to justify the cost.
What if I can't find good comparable sales?
If strong comps are difficult to find—which happens in unique properties or rural areas—focus on other evidence: property record errors, condition documentation, and external factors. You can also expand your search radius slightly or use comps from similar neighborhoods. Professional assistance can help identify comps you might have missed, especially with access to MLS data.
How far back can comparable sales go?
Ideally, use sales from the past 6-12 months. The more recent, the better. Sales older than 12-18 months are generally considered less relevant by assessors. In slow markets with few transactions, you may need to go back further, but always prioritize the most recent sales available.
Can I submit additional evidence after filing my appeal?
For informal reviews, you generally cannot add evidence after your initial submission. That's why it's critical to be thorough and organized before you file. For formal hearings (County Board of Equalization), you may be able to present additional evidence at the hearing, but it's best to include everything upfront.