How to Appeal Property Taxes in Westchester County, New York (2026 Guide)

For most Westchester town assessment rolls, the 2026 property-tax grievance deadline was Tuesday, June 16, 2026: the rule is “the third Tuesday in June.” File Form RP-524, Complaint on Real Property Assessment, with your city or town assessor / Board of Assessment Review (BAR)—not with Westchester County. Because today is after the 2026 town deadline, the next standard town Grievance Day is Tuesday, June 15, 2027; cities such as Yonkers and White Plains use different charter calendars, so city homeowners must check the city assessor page.

How assessments work in Westchester County

Westchester is unusual because the County does not set your home’s assessment. Your local assessing unit—city or town—places the value on the assessment roll. Westchester County then uses local rolls, equalization, and tax warrants to spread county taxes across municipalities. The county’s own primer explains that cities and towns collect county, school, local, and special-district taxes, and that equalization rates are used because Westchester municipalities assess at very different percentages of full value.

For many Westchester towns, the practical 2026 calendar was: valuation date July 1, 2025; taxable status date May 1, 2026; tentative roll June 1, 2026; Grievance Day June 16, 2026; and final roll September 15, 2026. Greenburgh’s official calendar is a good example of the Westchester town schedule. A grievance reduction on the September final roll generally first affects the next town/county bill and the following school bill.

Reassessment is also local. New York’s 2026 statewide list shows recent reassessments in several Westchester assessing units—Greenburgh, Mamaroneck, North Salem, Ossining, Pelham, and one Rye listing show 2026—while many others are listed as “Prior to 1974” or older years. That means your strategy depends heavily on where you live: in a full-value town like Greenburgh, your assessment should look close to market value; in a low-ratio municipality, you must translate market value into assessed value using the local level of assessment / equalization information.

Whether you should appeal

Appeal if the roll value is higher than what your home would likely have sold for on the relevant valuation date, or if your home is assessed more harshly than comparable homes. For a one-, two-, or three-family home, the strongest evidence is usually: recent arm’s-length sales of similar homes near you, a recent appraisal, your own recent purchase price if it was market-based, photos and contractor estimates showing condition problems, and proof of incorrect inventory such as wrong square footage, bathroom count, finished basement, or lot characteristics.

Do not appeal just because your tax bill went up. A tax bill can rise because the school, county, town, fire, sewer, or village levy changed. The question for the BAR is narrower: is the assessment on the tentative roll excessive, unequal, unlawful, or misclassified? Form RP-524 has separate grounds for those categories.

Also check exemptions before you grieve value. In Westchester, common homeowner items include STAR credit/exemption, Enhanced STAR for eligible seniors, senior citizens exemption, veterans exemptions, disability/limited-income exemptions, clergy, volunteer firefighter/ambulance exemptions where adopted, and local homestead/non-homestead classification if your assessing unit uses it. Exemption deadlines are local; Greenburgh lists May 1 as its exemption deadline. A grievance can challenge a wrongly denied exemption, but it is better to file exemption paperwork on time.

I did not find an official countywide published “success rate” or median homeowner reduction for Westchester grievances. Yonkers’ FY2026 budget publishes workload counts—thousands of BAR appeals and hundreds of SCAR appeals—but not win rates or median reductions. Treat anyone promising a “typical” reduction with caution unless they can show municipality-specific public data.

Step-by-step how to file

1. Find the right assessing unit. Use your tax bill, municipal website, or Westchester parcel viewer to confirm whether your property is in a city, town, village, school district, and special districts. File the grievance with the assessor or BAR for the city or town that assessed the parcel. If you are in a village that prepares its own assessment roll, you may have a separate village grievance too.

2. Download the exact form. Use New York Form RP-524, “Complaint on Real Property Assessment Before the Board of Assessment Review,” plus RP-524-Ins instructions. A separate complaint is generally filed for each separately assessed parcel. There is no standard state/county filing fee for the administrative RP-524 grievance; the later court-level SCAR petition has a $30 filing fee.

3. Compute the reduction you are asking for. If the municipality assesses at full value, your requested assessment is your supported market value. If it assesses at a fraction of value, multiply your supported market value by the local assessment ratio. Be careful: the state instructions warn that asking for too small a reduction can limit later relief.

4. Attach evidence, not a rant. Include a short cover letter, 3–6 comparable sales, photos, appraisal or broker CMA if you have one, and proof of inventory errors. Label each attachment. If your argument is an exemption denial, attach the exemption application and denial/notice.

5. File by the local method and deadline. New York instructions allow filing with the assessor or BAR and say mailed complaints must be received by Grievance Day. Local methods differ. Greenburgh’s 2026 homeowner packet said formal RP-524 filings were accepted June 1 at 9 a.m. through June 16 at 9 p.m., by hand delivery or mail to Town of Greenburgh, Assessment Department, 177 Hillside Ave., Greenburgh, NY 10607; it specifically said postmarked mail, emailed applications, and emailed documentation would not be accepted. Greenburgh also offered a separate informal online review portal from May 15 to June 11 at 11:59 p.m., but that was not the formal grievance.

Other Westchester cities can be very different. White Plains says its BAR meets under the City Charter on January 21 and accepts applications January 1–January 21 at the Assessor’s Office, 255 Main St., White Plains, NY 10601. Yonkers publishes a November filing window for its tentative roll and uses City Hall, 40 South Broadway, Room 100, Yonkers, NY 10701 for assessment filings. Always use the local assessor’s current instructions.

What happens after

The appeal authority is the Board of Assessment Review for your assessing unit. It is not a court and it is not the Westchester County Tax Commission. You may appear yourself, use an attorney, or designate a representative in Part Four of RP-524.

The hearing can be brief. In Greenburgh, once your application is filed, you may schedule a BAR appointment, but the town says appearing is not mandatory for your documents to be reviewed; 2026 appointments were limited to 10 minutes. The BAR can ask you or your representative to appear or provide more proof. The state instructions say the BAR must mail a determination notice with reasons unless it ratifies a stipulation.

For Westchester towns on the September 15 final-roll schedule, decisions are commonly mailed around final roll. Greenburgh’s packet says determinations are received on or around September 15, and its calendar says homeowners then have 30 days—shown locally as September 15 to October 15—to challenge by Small Claims Assessment Review. Statewide, SCAR or tax certiorari generally must be started within 30 days after the final roll is filed or notice of filing, whichever is later.

SCAR is for qualifying owner-occupied one-, two-, or three-family homes and certain small vacant residential parcels. It is filed in New York Supreme Court using the court system’s SCAR petition process and is heard by a trained hearing officer. The fee is $30. Commercial properties and more complex cases usually require an Article 7 tax certiorari proceeding.

Local tips

Use Westchester-specific rates when estimating savings. Example: assume an Edgemont school-district homeowner in Greenburgh’s town-outside-villages area proves a reduction from $900,000 to $850,000—a $50,000 assessment reduction. Greenburgh’s 2025–2026 school sheet lists Edgemont at $19.7773 per $1,000. The 2026 town/county sheet shows town-outside-villages at $5.503765 and county tax at $2.267751 per $1,000. Before fire, sewer, village, and special districts, the annual savings estimate is: $50,000 ÷ 1,000 × ($19.7773 + $5.503765 + $2.267751) = about $1,377 per year. Add applicable fire, sewer, village, or refuse rates for a truer parcel-specific estimate.

Finally, compare within the same municipality and school district whenever possible. Westchester ZIP codes cross municipal lines, and two nearby houses can be in different towns, villages, school districts, or fire districts. The best appeal packet looks local: your assessment notice, your property record card, sales in your neighborhood, and the exact tax-rate area on your bill.