How does the Texas homestead 10% appraisal cap interact with my protest?

The Texas homestead cap is one of the most misunderstood numbers on a notice of appraised value, and it changes whether protesting will actually lower your bill.

What the cap does. Under Tex. Tax Code §23.23, once you qualify for a residence homestead exemption, the appraised (capped) value used for taxes may not increase by more than 10% per year. Specifically, your capped value is the lesser of (1) the market value, or (2) last year's appraised value plus 10%, plus the market value of any new improvements. The limitation takes effect on January 1 of the tax year after the first year you qualify for the exemption.

Why your notice shows two numbers. Your appraisal district lists both a market value (what the district thinks the home is worth) and a capped/appraised value (the lower number the cap holds down). In a rising market the gap can be large — your market value might be $500,000 while your capped value is only $380,000. You are taxed on the capped value (minus exemptions), per Tex. Tax Code §23.23 and the Texas Comptroller's valuing-property guidance.

The protest implication. If your capped value is already far below market value, knocking the market value down a little may not lower your taxes this year — the cap is still controlling. To get a bill reduction you generally need to push the market value below your capped value, or win on unequal appraisal under Tex. Tax Code §41.43(b)(3), which is measured against comparable homes.

When protesting still helps despite a cap:

• The market value is genuinely wrong and you can drive it below your capped value.
• Your home is unequally appraised relative to neighbors (the equal-and-uniform ground ignores the cap math and looks at fairness).
• Future years: even if this year's bill doesn't move, lowering the market value can slow how fast the cap pushes your value up next year, because the 10% increase builds on the prior appraised value.
• A factual error (square footage, an improvement that doesn't exist) is inflating the market value.

Note for new buyers: the cap resets after a change of ownership, so your first full year may show a large, uncapped jump toward market value — a common reason to protest. Check both numbers on your notice before deciding whether a protest will pay off this year or set you up for the next.