New Jersey consistently carries the highest effective property taxes in the country, which makes a successful appeal especially valuable — and the state's system has a quirk that decides many cases before you ever argue value: the Chapter 123 ratio test.
The deadline
In most years, you appeal to your County Board of Taxation by April 1. In a taxing district that has done a revaluation or reassessment, the deadline moves to May 1. Assessment notices go out around February 1, so the window is short — calendar it the moment your notice arrives.
File the right form — and know when to skip the county board
You file a Petition of Appeal (Form A-1) with the County Board of Taxation. If your property's assessed value exceeds $1,000,000, you have the option to file directly with the New Jersey Tax Court instead of the county board.
The Chapter 123 ratio test — New Jersey's key
Because assessments in a town are all set to a common level, New Jersey applies each district's average ratio (the 'Chapter 123' ratio) with a corridor of plus or minus 15% around it. The board divides your assessment by that ratio to find your implied market value. If your assessment falls within the corridor, it stands; if it exceeds the upper limit, the board reduces your assessment to the average ratio times true value. Winning often comes down to proving a true market value low enough to push you past that upper limit.
Evidence that wins in New Jersey
- Recent arm's-length comparable sales in your district, as close to the October 1 valuation date as possible.
- Your own recent purchase price, if you bought near the valuation date.
- A formal appraisal for higher-value or unusual properties, especially at the Tax Court level.
After the county board: Tax Court
If you disagree with the county board judgment, you can appeal to the New Jersey Tax Court, generally within 45 days of the board's decision. The Tax Court is more formal and typically expects an appraiser.
Find your district's current average ratio before you file — it tells you exactly how low a market value you need to prove to win under Chapter 123.
Sources & currency: New Jersey appeal deadlines, the $1,000,000 direct-to-Tax-Court threshold, and the Chapter 123 ratio corridor were verified against the New Jersey Division of Taxation as of July 2026. Ratios are set per district each year — confirm yours and your deadline before filing.