Valuation date
The date your assessment is supposed to reflect, often more than a year before the bill.
Assessments describe value as of a fixed date — January 1 of the tax year in many states, sometimes earlier, sometimes an average of several years.
This is why 'but the market has fallen since' often fails. If the valuation date is January 1 and the market moved in June, the June movement belongs to a different tax year's appeal.
It also decides which sales are usable as evidence. Sales close to the valuation date carry weight; sales well after it invite the argument that they describe a different market.
Related
- Market value — What a willing buyer would pay a willing seller, neither under pressure.
- Tax year — The year an assessment applies to, which is often not the year you pay.
- Comparable (comp) — Another property used as evidence — either its sale price or its assessment.
Property tax is state law and the details differ. For what applies where you live, see coverage by state and your appeal deadline.