Which form do I use to grieve my New York property taxes, and when is it due?

The form and the date, by where you live

The dates for towns come from the state's own grievance procedures page: most communities hold Grievance Day on the fourth Tuesday in May, Suffolk County towns on the third Tuesday in May, Westchester County towns on the third Tuesday in June, and villages that assess typically on the third Tuesday of February. The 2026 dates have passed. The 2027 dates above are the calendar dates those rules produce, and your tentative roll, published around May 1, is the official trigger.

Nassau County and New York City are separate systems with their own forms and calendars, which is why a search for the New York grievance form turns up three different answers. All three are correct for their part of the state.

Form RP-524 in plain terms

Form RP-524, Complaint on Real Property Assessment, is the statewide form. The current revision is dated 3/09 and its instructions are Form RP-524-Ins. The state says the form can be completed by yourself or your representative or attorney, that there is no cost to grieve an assessment, and that it does not require you to hire a lawyer.

You give the property and owner details, state the assessed value you believe is correct, and choose your grounds. For a home the usual ground is unequal assessment: your home is assessed at a higher fraction of value than comparable homes nearby. The complaint goes to the assessor or the Board of Assessment Review in your city or town, on or before Grievance Day.

What happens on Grievance Day and after

1. 1The Board of Assessment Review has three to five members and cannot include the assessor or the assessor's staff. You may appear in person, with or without an attorney, or let the written complaint speak.
2. 2The board decides after the hearing and the final roll follows, filed by July 1 in most towns.
3. 3If you disagree, an owner-occupant of a one, two or three family home can file Small Claims Assessment Review in court within 30 days of the filing of the final assessment roll, for a $30 fee. You must have grieved to the board first. Other owners use a tax certiorari proceeding under Article 7.
4. 4In Nassau County, the 2027/28 roll's ARC window closed March 2, 2026; its final determinations go out by March 31, 2027, the final roll publishes April 1, 2027, and the Small Claims deadline for that roll is April 30, 2027. The next ARC filing window is January 4 to March 1, 2027.

What to do now, months before the window

Most of the state is between windows until spring. That is the right time to check the assessor's record card for your home, correct square footage or condition errors, and gather three to five comparable homes assessed lower per square foot than yours. The free check compares your assessment to similar properties where we hold roll data, and the $29 New York DIY kit organizes the record review, comparables and the RP-524 or AR1 filing plan so the form takes minutes when the date arrives.

The full process, with the evidence that wins, is in how to grieve property taxes in New York and, for Long Island's largest county, how to grieve in Nassau County.