How to Find Comps for a Property Tax Appeal (and Which Ones Actually Count)
Your county says your home is worth $410,000. Three houses on your street sold for $370,000 last spring. That gap is your entire appeal, and it is built out of comparable sales. Here is how to find the right ones, for free, and present them so a review board takes you seriously.
Why Comparable Sales Decide Appeals
Your assessed value was not set by someone walking through your house. It came from mass appraisal: an algorithm that estimates thousands of parcels at once, using the same recent-sales data you are about to go find. The model cannot see your outdated kitchen, the busy road behind your lot, or the roof you patched instead of replaced.
That is the opening. When you show the review board real market transactions where similar homes sold for less than your assessed value, you are speaking their language. The sales comparison approach is the primary valuation method review boards use for residential property, so an appeal built on solid comps lands on ground they already accept. Arguments about affordability, or that taxes just feel too high, do not meet that standard, no matter how true they feel.
So the job is narrow: find 3 to 5 recent sales of genuinely similar homes near yours, document them cleanly, and let the numbers do the arguing.
What Makes a Comp Count
Not every nearby sale qualifies. A board member will dismiss a comp in seconds if it fails any of these tests, so filter before you file.
1. Close to you
The ideal comp is in your neighborhood or subdivision. Within half a mile is excellent; stretching to a mile is common in rural areas. The further the sale happened from your home, the easier it is for the board to say a different submarket drove the price.
2. Recent
Sales within the last 6 to 12 months are the standard window, and fresher is stronger. In Texas, protest specialists recommend sales within 90 days where possible. Sales also need to be near your jurisdiction's valuation date, the January 1 lien date in states like California and Georgia. A sale from three years ago tells the board nothing about this year's market.
3. Similar to your home
This is where most DIY appeals fall apart. A good rule of thumb: square footage within about 10 percent of yours, lot size within about 15 percent, age within 5 to 10 years, and the same general condition and feature set. A renovated 3,400-square-foot colonial with a pool is not comparable to your 2,200-square-foot ranch with a 20-year-old roof, even on the same street. Match beds, baths, garage, basement, and finishes as closely as the data allows.
4. An arm's-length sale
The sale has to reflect the open market. Foreclosures, short sales, bank-owned transfers, and sales between family members get discounted or thrown out by the board. You want ordinary buyers and sellers who had no relationship and no distress.
5. Below (or at least near) your assessed value
This sounds obvious, but say it plainly: the comps you bring should support a lower number. If your home is assessed at $410,000 and your best comps sold for $425,000, you do not have an appeal. You have confirmation the assessment is fair.
Where to Find Comps for Free
You do not need a paid subscription to build a credible comp set. Start with these, in this order.
Your county assessor's website
This is the source I would start with every time. Most counties now have an online property records portal where you can look up parcel records, assessed values, and recorded sale prices. It is public information by law, and because the board pulls from the same system, data from this source carries weight. Search your county name plus "property records" or "assessor parcel search."
Zillow's sold listings
Search your address on Zillow, then filter to recently sold homes nearby. The critical distinction: use actual sold prices, never the Zestimate. A Zestimate is a model estimate, and a board will treat it as an opinion, not evidence. The sold listing with a recorded price and date is what counts.
Redfin and Realtor.com
Redfin's sold data tends to be clean and includes price history and days on market, which helps you spot distressed or stale listings. Realtor.com is a good second check for sales Zillow missed. Cross-referencing two sources also catches data-entry errors.
A local real estate agent
A buyer's agent in your neighborhood can pull true MLS comps in ten minutes, often for free, because you are a potential future client. MLS data is more accurate than aggregator sites on square footage, condition notes, and sale terms. If your online search is thin, one friendly agent is the fastest fix.
Aim for 5 to 10 candidates, then narrow to your best 3 to 5. Start wide so you can throw out the weak ones, the foreclosure, the flip with a gut renovation, the one two miles away, and still have a strong set left.
A Worked Example: Turning Comps Into a Case
Say your assessment notice values your home at $410,000. You pull sales from the last eight months within your subdivision:
| Address | Sold | Price | Sq ft | Notes vs. your home |
|---|---|---|---|---|
| 118 Maple Ct | Mar 2026 | $372,000 | 2,150 | Same model, updated kitchen (+$10k) |
| 204 Maple Ct | Jan 2026 | $365,000 | 2,080 | Smaller lot, similar condition |
| 97 Oak Dr | Nov 2025 | $381,000 | 2,220 | New roof, yours is 15 years old |
| 311 Pine Ln | Jun 2026 | $370,500 | 2,110 | Backs to main road, like yours |
The argument writes itself. Four arm's-length sales of similar homes, all within a half mile, all in the last 8 months, sold for $365,000 to $381,000. Two of them are in better condition than your home. Your $410,000 assessment sits $30,000 to $45,000 above every data point the market produced. A reasonable requested value: $375,000, right in the middle of the comp range.
At a 1.5 percent effective tax rate, that $35,000 reduction is worth about $525 a year, every year the corrected value stands. Run your own numbers through our appeal savings calculator to see what a similar reduction would save you.
Notice what I did with the differences: I adjusted for them in words instead of pretending the homes are identical. When a comp is nicer than yours, say so. It makes your case stronger, not weaker, because it shows you are being honest and the conclusion still favors you.
How to Present Your Comps
Board members review dozens of cases in a sitting. Make yours the easy one. Put your 3 to 5 best comps on a single page: address, sale date, sale price, square footage, lot size, year built, distance from your home, and one line on how it compares. Attach the source for each, the MLS listing printout, the county record, or the Redfin sold page.
Then add a short cover note: your assessed value, the value you are requesting, and the sentence that ties it together. Something like: "Four comparable homes sold between November 2025 and June 2026 for $365,000 to $381,000. I request the assessed value be reduced from $410,000 to $375,000 to reflect market value." Calm, specific, and short beats long and emotional every time.
Comps That Will Hurt You
A few traps I see homeowners walk into:
Cherry-picking only the cheapest sales. If the board's own data shows six similar sales and you brought the three lowest, you lose credibility. Include the full range and let the middle of it carry your argument.
New construction down the street. New builds sell at a premium and are not comparable to an existing home. Leave them out.
Your neighbor's lowball assessment. "My neighbor pays less" is an equity argument, not a market-value argument. Some boards hear it, but it is weaker than sales and can make you look like you are complaining rather than proving.
Stale or distant sales. A comp from two years ago or three miles away invites the response "the market has changed" or "different neighborhood." Stick to your window.
Frequently Asked Questions
How many comps do I need for a property tax appeal?
Three to five strong comps is the sweet spot most guides and protest firms recommend. One comp looks like an anecdote; ten looks like you could not decide. Quality beats quantity every time.
Can I use my home's Zestimate as evidence?
No. A Zestimate is an automated estimate, and boards treat it as an opinion. Use Zillow's actual sold listings, with recorded sale prices and dates, which are market facts.
What if no similar homes sold near me recently?
Widen the search in this order: expand the radius slightly, then expand the time window, then loosen the similarity criteria a little and adjust in words. A local agent's MLS search is the best fallback. If truly nothing sold, condition evidence and record errors become your primary case instead.
Should I include comps that sold for more than my assessed value?
If they are the most similar sales available, yes, include the full honest range. Omitting inconvenient sales damages your credibility if the board has the same data. Most of the time, though, high comps mean the assessment is roughly right and an appeal may not be worth filing.
Related Reading
Gathering comps is a free afternoon of work, but it is not the only way to get an appeal filed. If you are weighing whether to do this yourself or hand it off, read what property tax appeal companies actually charge, and when DIY wins.
Estimate What Your Appeal Could Save
Found comps that sit below your assessed value? Plug in your numbers to estimate the yearly savings before you file, then check your state's appeal deadline.
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