Can You Use Zillow Estimates in a Property Tax Appeal?
TL;DR
Zillow Zestimates are not accepted as evidence by most review boards. They are algorithm-generated estimates based on public data, not actual market transactions. Review boards want real comparable sales data showing what buyers actually paid. Use Zillow as a research tool to find recently sold homes, but do not cite the Zestimate itself as evidence of value.
Why Boards Reject Zestimates
- Not a market transaction. A Zestimate is a computer model output, not evidence of what a buyer would pay.
- Known accuracy issues. Zillow's own disclosures show median error rates of 2-7% depending on the market. In some areas, errors exceed 15%.
- No property inspection. The algorithm does not know your home's condition, interior quality, or unique features.
- Not prepared by a licensed professional. Unlike an appraisal or CMA, no licensed person vouches for the accuracy.
What Boards Do Accept
| Evidence Type | Accepted? | Weight |
|---|---|---|
| Comparable sales from county records | Yes | High |
| MLS sales data | Yes | High |
| Professional appraisal | Yes | High |
| Agent CMA letter | Yes | Moderate |
| Zillow/Redfin sold data (actual sales) | Yes | Moderate |
| Zillow Zestimate | No | None |
| Redfin Estimate | No | None |
How to Use Zillow Correctly
Zillow is useful for research, not evidence:
- Use the "Recently Sold" filter to find comparable sales
- Use the map to identify similar homes in your area
- Note sale prices, dates, and property details from actual sold listings
- Then verify the data against county records before using it in your appeal
For guidance on proper evidence sources, see our evidence guide.
Get Professional Evidence for Your Appeal
Our $79 Evidence Packet provides comparable sales analysis from multiple data sources, formatted and ready for your appeal hearing.