Short answer: Across Dallas County, over-assessment clusters by city. Our analysis of public DCAD appraisal data found the highest rates in Richardson (about 20% of homes), Farmers Branch, and Mesquite, where homes are most often valued above truly comparable neighbors. The largest dollar gaps, though, are in Highland Park — where an over-assessed home is off by roughly $343,000 on average.
- Richardson leads Dallas County at ~20% of homes over-assessed.
- Highland Park has the largest dollar gaps — about $343,000 on average.
- Even the city of Dallas, with 229,000 homes analyzed, runs over 15%.
- A high city-wide rate doesn't mean your specific home is over-assessed.
- Over-assessment is decided home-by-home against your own comparables.
Which Dallas-area cities are most over-assessed?
We analyzed Dallas Central Appraisal District (DCAD) records for hundreds of thousands of homes and compared each one to truly comparable neighboring properties — the same neighborhood, property class, and era of construction. Homes valued more than 10% above the median of their peer group were flagged as likely over-assessed, the same equal-and-uniform standard used in a Texas protest.
Because Dallas County is a patchwork of distinct cities, we grouped the results by city rather than ZIP code.
How we measured over-assessment
Texas law says your home should not be appraised higher than comparable homes around it (Texas Tax Code §41.43(b)(3)). We applied that principle at scale:
- We grouped every residential parcel with truly comparable homes — matched on DCAD neighborhood code, property class, and decade built.
- Within each group, we found the median improvement value per square foot.
- Any home more than 10% above its group’s median was flagged as likely over-assessed, and we estimated its gap.
These are estimates from public data, not official determinations — but they mirror the exact evidence an appraisal review board weighs in a protest.
Rate isn't the whole story: Highland Park vs. Richardson
Two very different cities top our lists in two different ways. Richardson has the highest share of over-assessed homes (about 1 in 5), but its average gap is modest. Highland Park has a lower share — yet its over-assessed homes are off by roughly $343,000 each, by far the largest dollar gaps in the county.
The lesson: in high-value cities, even a small percentage over-assessment is a lot of money. If you own an expensive home, a smaller-looking gap can still mean thousands of dollars a year in overpaid taxes.
What this means for your home
A high city-wide rate does not mean your home is over-assessed — and a low rate does not mean it isn’t. Every city on this list has thousands of homes, and over-assessment is decided property-by-property against your specific comparables.
The only way to know is to check your own address. If your home is valued above its comparable neighbors, that gap is money you may be overpaying in property taxes every year — and it’s the basis for a protest.
Dallas County cities by over-assessment rate (2026)
| City | Homes analyzed | % over-assessed | Avg. estimated gap |
|---|---|---|---|
| Richardson | 20,687 | 20.4% | $55,000 |
| Farmers Branch | 8,627 | 19.1% | $45,000 |
| Mesquite | 37,025 | 16.5% | $31,000 |
| Carrollton | 11,128 | 16.2% | $45,000 |
| Garland | 60,226 | 15.9% | $36,000 |
| Sunnyvale | 2,842 | 15.4% | $75,000 |
| Dallas | 229,045 | 15.3% | $71,000 |
| Balch Springs | 5,661 | 14.4% | $28,000 |
| Highland Park | 3,129 | 13.9% | $343,000 |
| Rowlett | 18,566 | 13.9% | $42,000 |
- ↑Complete guide: Using County Appraisal Data to Lower Your Property Taxes
- ›Understanding Your Travis County Property Appraisal: Key Factors That Influence Your Home's Value
- ›How Texas Appraisal Districts Calculate Your Home's Value
- ›How to Access TCAD Appraisal Data for Your Travis County Property Tax Protest
Check your home in minutes
Tax Gaps TX has a free home check at app.taxgapstx.com/check — enter your address and, in about a minute, see your estimated over-assessment gap for Travis (TCAD) or Dallas (DCAD) county, based on public appraisal data and comparable homes assessed for less than yours. A specialist can then walk you through the evidence and whether it's worth protesting.
Frequently asked questions
Does a high city rate mean my home is over-assessed?
No. Over-assessment is decided home-by-home against your specific comparable properties. A high-ranked city just means a larger share of homes there are over-assessed — your home could be fine, or a home in a lower-ranked city could be significantly over-assessed.
Why is Highland Park's dollar gap so much larger?
Highland Park has some of the most expensive homes in Texas, so even a modest percentage over-assessment translates into a very large dollar amount. Rate and dollar impact are two different things.
How do I check whether my own home is over-assessed?
Enter your address at app.taxgapstx.com/check. We pull DCAD appraisal data, find comparable homes assessed for less, and show your estimated gap — the evidence you'd use to protest.
Is this an official DCAD determination?
No. These are estimates built from public DCAD data for informational purposes. Confirm any figures with the Dallas Central Appraisal District before filing a protest.
Tax Gaps TX provides general information, not legal, tax, or financial advice. Deadlines and exemption amounts change; confirm current figures with your county appraisal district or the Texas Comptroller.