First, the math on whether it’s worth it
An appeal is worth your evening if (over-assessment amount) × (your effective rate) is meaningful. Example: you believe the assessor is $60,000 high and your effective rate is 2% — that’s $1,200 a year, every year, for a few hours of work. If the gap is $10,000 at a 0.7% rate, that’s $70; skip it.
Grounds that actually win
- Factual errors: wrong square footage, bedroom count, lot size, or a garage you don’t have. Check your property record card first — these are the fastest wins.
- Comparable sales: 3–5 recent arm’s-length sales of similar nearby homes below your assessed value. This is the core of most successful appeals.
- Condition issues the model can’t see: foundation problems, water damage, deferred maintenance — documented with photos and repair estimates.
- Unequal assessment: in some states you can argue your home is assessed higher than comparable homes are, even if it’s not above market value.
The process, generically
It’s usually: informal review with the assessor → formal appeal to a local board (Texas’s Appraisal Review Board, Michigan’s March Board of Review) → state tribunal or court if needed. Most cases end at the board. Deadlines are short and unforgiving — often 30 days from your notice — and vary by state; your county’s deadline is listed on our county pages.
One caution
An appeal can theoretically raise your assessment if the review finds you’re under-assessed — rare, but check whether your home is genuinely below market before you invite a second look.