What Every Long Island Homeowner Should Know Before Filing a Property Tax Grievance

How to file a property tax grievance in New York comes down to these core steps:

Check your tentative assessment on your local assessment roll (published around May 1st)
Estimate your property’s market value using recent comparable sales
Complete the correct form – Form AR-1 for Nassau County
Submit before the deadline – Nassau County: January 2nd through March 1st. It is sometimes extended to give homeowners more time to file.
Appear before the Assessment Review Commission (ARC) or authorize a representative
If denied, escalate to Small Claims Assessment Review (SCAR) within 30 days of the final assessment roll

Here’s something most Long Island homeowners don’t realize: your property tax bill is not fixed. If your home has been assessed at a value higher than what it would actually sell for on the open market, you have the right to challenge it – at no risk. A failed grievance cannot cause your taxes to increase.

Yet most homeowners never file. Some don’t know the process exists. Others find it confusing and time-sensitive. And the stakes are real: Nassau County’s median effective property tax rate is among the highest in the nation.

I’m Adam Heller, founder of Heller Tax Grievance. After spending years in Long Island real estate and watching high property taxes directly affect home values and affordability, I left real estate specifically to help homeowners understand how to file a property tax grievance and pay only their fair share. This guide walks you through exactly how to do it.

Understanding the Property Tax Grievance Process

When we talk about Understanding Property Tax Grievance, we are essentially discussing an administrative review of your home’s value. In New York, the law requires that all properties be assessed at a uniform percentage of value. If your assessment is higher than that uniform percentage, you are being overcharged.

The process is designed to be accessible to the public. You don’t need a JD from Harvard to navigate it, but you do need to understand the local Grievance procedures. The “administrative review” is the first level of this process. It takes place at the municipal level, where a Board of Assessment Review (BAR) or an Assessment Review Commission (ARC) looks at your evidence.

Key terms you need to know:

Fair Market Value: The price a willing buyer would pay a willing seller in an open market.
Taxable Status Date: In most New York towns, this is March 1st. It is the date the assessor determines the physical condition of your property.
Tentative Assessment Roll: The list of all property assessments in the municipality, usually published on May 1st. This is your “warning shot” to see if your taxes are about to spike.

Who is Eligible to File?

Generally, any person “aggrieved” by an assessment can file. This includes:

Property Owners: The most common filers.
Purchasers: If you have a contract to buy the home, you can often file.
Tenants: If your lease requires you to pay the property taxes, you have skin in the game and the right to grieve.

Whether you live in Rocky Point, Miller Place, or the high-end estates of Upper Brookville, the eligibility remains the same. Specifically, Suffolk County Tax Grievance Eligibility focuses on owners of residential 1-3 family homes and condominiums. If you own a vacant lot under 10 acres in certain zones, you might also be eligible.

Key Deadlines and the Tax Grievance Calendar

Missing a deadline is the number one reason grievances fail before they even start. New York does not offer “oops” extensions for tax filings. You must be aware of the Tax Grievance Deadlines for your specific area.

Valuation Date: This is the date upon which the value of your property is based. For many towns, the valuation date for the 2025/26 tax year was July 1, 2024.
Final Assessment Roll: This is published after the grievance process is complete, usually around July 1st.

How to File Property Tax Grievance in Nassau County

Nassau County is a bit of an outlier in New York. While most of the state follows a May schedule, Nassau operates on its own timeline. To start your Nassau County Grievance Application, you deal with the Assessment Review Commission (ARC) located in Mineola.

The standard filing window is January 2nd to March 1st. However, for the 2025/26 cycle, this has been extended to March 31st. You must use Form AR-1. In Nassau, residential properties (Class 1) are often assessed at a tiny fraction of market value (sometimes around 0.1%), which makes the math confusing. Our Ultimate Nassau County Tax Guide breaks down these ratios so you don’t need a calculator and a prayer to figure out if you’re overassessed.

Filing in Suffolk County and Other NY Towns

In Suffolk County—including towns like Huntington, Brookhaven, and Smithtown—the deadline is almost always the third Tuesday in May. This is known as “Grievance Day.”

To file your Suffolk County Grievance Application, you use Form RP-524. You must submit this to the town assessor’s office or the BAR. Unlike Nassau, many Suffolk towns have a Residential Assessment Ratio (RAR) that is slightly more straightforward, such as Huntington’s 2025 RAR of 0.42%. If you want to Contest your assessment in these towns, you generally have until the close of business on Grievance Day to get your paperwork in.

Step-by-Step Guide: How to File Property Tax Grievance Successfully

Filling out the paperwork is the “meat” of the process. If you are outside of Nassau County or NYC, you will be Completing the grievance form – Tax.NY.gov known as RP-524. Here is the breakdown:

Part 1: General information about you and the property. Use the info exactly as it appears on your tax bill.
Part 2: This is where you list your estimate of the property’s value. Be realistic. If you ask for a reduction to $100,000 on a home worth $800,000, the BAR will likely toss your application for lack of credibility.
Part 3: Grounds for complaint. You must select one of four: Unequal, Excessive, Unlawful, or Misclassification. Most homeowners choose Excessive (the assessment is higher than the full value) or Unequal (you are assessed at a higher percentage than your neighbors).
Part 4-6: These sections cover representative authorization, certification, and stipulations.

For more detailed strategies, we recommend reviewing our 15 Tips for Appealing Your Property Tax Assessment.

Determining if Your Property is Overassessed

To how to file property tax grievance effectively, you first have to prove you’re actually overassessed. You do this by calculating your “Indicated Market Value.”

Find your Total Assessment on your tax bill.
Find your town’s Residential Assessment Ratio (RAR) or Equalization Rate.
Divide the Assessment by the RAR.

For example, in the Town of Huntington, if your assessment is 4,100 and the RAR is 0.42%, the math is 4,100 / 0.0042 = $976,190. If your home is only worth $800,000, you have a very strong case. You can Determine if You Have a Grievance Case by looking at recent sales of similar homes in your immediate neighborhood.

Gathering Evidence to Support Your Claim

The BAR doesn’t take your word for it. You need proof. Our Complete Guide to Property Tax Grievances emphasizes these four types of evidence:

Comparable Sales: Find 3-5 homes similar to yours that sold within the last year. Adjust for differences—if a neighbor’s house has a pool and yours doesn’t, their sale price should be adjusted downward for the comparison.
Professional Appraisals: An independent appraisal is the gold standard of evidence.
Property Photos: If your kitchen hasn’t been updated since 1974 or you have a cracked foundation, show them! The assessor assumes every house is in “good” condition unless proven otherwise.
Repair Estimates: Got a roof leak or a mold issue? Get a written estimate from a contractor. These costs directly reduce the market value of your home.

What Happens After You File Your Grievance?

Once you’ve submitted your paperwork, the BAR reviews it. You have the right to an administrative hearing, though you don’t have to attend in person if you’ve provided enough written evidence.

The Tax Grievance Process Explained usually results in one of three outcomes:

Full Reduction: They agree with your numbers completely.
Partial Reduction: They offer a “stipulation”—a middle-ground number.
Denial: They believe the current assessment is fair.

You will receive a notification of the results by mail. If you win, your tax bill will be adjusted. If you’ve already paid the higher amount, you may receive a refund, though this can sometimes take several months to process.

Judicial Review and Small Claims Assessment Review (SCAR)

If the BAR denies your claim or gives you a reduction that is too small, don’t give up. You can pursue a judicial review. For most homeowners in places like Syosset, Massapequa, or Stony Brook, this means filing a Small Claims Assessment Review (SCAR) petition.

Cost: There is a $30 filing fee.
Deadline: You must file within 30 days of the filing of the final assessment roll.
Process: You will have a hearing before a court-appointed hearing officer. It’s less formal than a trial but more structured than the BAR.

This is often where the biggest savings happen. In NYC, the process is similar but handled through the NYC Tax Commission, and for very high-value properties (assessed at $2M+), there is a $175 fee. You can find more on Property Value Appeal · NYC311.

Frequently Asked Questions about Property Tax Grievances

Can I file a grievance every year?

Yes! In fact, we recommend it. You can Can You Grieve Property Taxes Annually? because market conditions and town ratios change every single year. Even if you received a reduction last year, a shift in the local RAR or a dip in neighborhood home prices could mean you are overassessed again this year. Filing annually ensures you never pay more than your fair share as the market fluctuates.

Do I need a lawyer to file a grievance?

No, you are not legally required to have a lawyer. You can certainly choose the self-filing route. However, there are 5 Reasons to Hire a Tax Grievance Firm. Most homeowners don’t have access to the professional sales databases, advanced valuation software, or the time to attend SCAR hearings in the Supreme Court. Professional firms handle the paperwork, the evidence gathering, and the negotiations while you go about your day.

Will my taxes go up if I lose?

This is one of the Top 5 Property Tax Grievance Myths. The answer is a resounding no. By law, the grievance process is a one-way street: your assessment can stay the same or go down, but it cannot be increased because you filed a complaint. It is a no-risk proposition for the homeowner.

Conclusion

At Heller Tax Grievance, we’ve spent years perfecting the art of the tax appeal. We serve homeowners across Long Island—from Farmingdale to Deer Park and Brookville to Stony Brook. Our mission is simple: we believe no one should pay more than their fair share of the tax burden.

With our “You Don’t Pay Unless You Save” guarantee, there is absolutely no reason to leave your money on the table. We’ve saved our clients over $160 million, and we’re ready to help you next. Whether you’re in Nassau or Suffolk, the clock is ticking on this year’s deadlines.

Ready to see if you’re overassessed? Contact Heller Tax Grievance today for a free consultation. Let us handle the Property Tax Grievance process for you so you can focus on what matters—enjoying your home.