Nassau County property tax records are public files that show who owns each home and business in the county, how much it is worth, and how much tax is paid each year. These records cover more than 380,000 parcels across Long Island, from Hempstead and Levittown to Great Neck and Long Beach.
Anyone can look up these records for free using the county’s online tools. This page explains how to search, what each record means, and how to use the data for appeals, payments, or research.
What Are Nassau County Property Tax Records?
Property tax records are official papers kept by the county about every piece of real estate. They include the owner’s name, the address, the lot size, the building details, the assessed value, and the tax amount owed each year. Nassau County keeps these records so the government can fairly collect taxes and so the public can check who owns what property.
Who Maintains These Records?
Two county offices share this job. The Department of Assessment puts a value on every property each year. The Treasurer’s Office bills owners and collects the tax money. Both offices keep their own version of the same records, and both share the data online through the MyNassauTax.com portal.
What Information Do These Records Show?
A full tax record shows the parcel ID number, which Nassau County calls a Section, Block, and Lot number, or SBL. It shows the legal owner’s name, the property address, the lot size in square feet, the year the home was built, and the size of all buildings. It also shows the assessed value, any exemptions applied, and the final tax bill. Some records also show past sales prices, which helps buyers check market prices.
How to Search Nassau County Tax Records Online
The fastest way to look up a tax record is through the county’s online portal. The site is free to use and works on any phone or computer. You do not need an account. You can search by address, parcel number, or owner name depending on what you know.
Search by Address
If you know the house number and street name, type the full address into the search bar on MyNassauTax.com. The site will pull up the matching parcel, show the current tax status, and let you view a PDF copy of the latest tax bill. This works for any home, business, or empty lot in the county.
Search by Parcel ID Number
A parcel ID in Nassau County has three parts: a section number, a block number, and a lot number. The format looks like this: 49-225-123. You can find this number on an old tax bill or from a previous deed. Entering the SBL number gives the most exact search result and shows the full property record card.
Search by Owner Name
To find property by an owner’s name, type the last name first. You may need to try a few spelling options if the name is common. The search returns a list of parcels tied to that person, including the address and current tax balance. This is useful for landlords, heirs, or buyers checking a seller’s other holdings.
View Tax Payment History
Once you find a property, the portal shows the last five years of tax bills and payment dates. You can see if a bill is paid, unpaid, or late. You can also print a copy of any past bill for use in court, loan applications, or tax document reviews.
How Nassau County Assesses Property
Every year, the Department of Assessment sets a market value for each property. This value is the base used to calculate the tax bill. The county uses a process called mass appraisal, which means they look at recent sales of similar homes nearby to set each value.
The Assessment Process Explained
On a date called the taxable status date, the county looks at what each property could sell for on the open market. They check sales from the past year in the same neighborhood. They then place that value on the roll for the next tax year. Property owners do not need to file a return every year for their home, but they should check the new value each spring when the tentative roll comes out.
Key Dates in the Tax Calendar
The tax year runs on a fixed schedule. Missing a date can mean you lose a right to appeal or face a late fee. The table below shows the most important dates for most property owners.
| Date or Window | What Happens |
|---|---|
| January 1 | Taxable status date for the next roll |
| May 1 | Tentative assessment roll published |
| June 1 | Grievance application deadline |
| July 1 | Final assessment roll published |
| January 1 to March 31 | Tax bills issued and first payment window |
Property Tax Exemptions You Can Claim
Exemptions lower the value of your home that the tax is based on. Most owners qualify for at least one exemption. Some reduce the bill by a small amount, while others cut thousands of dollars from what you owe each year.
Basic STAR Exemption
The School Tax Relief, or STAR, program cuts part of your school tax bill. Most owner-occupied homes that serve as the main residence qualify. The savings show up as a credit on the school portion of the tax bill. You must apply through the New York State Department of Taxation and Finance, not the county. The county then applies the credit to your bill.
Enhanced STAR for Seniors
Homeowners age 65 and older with lower income can apply for Enhanced STAR. This gives a larger cut from the school tax. You must reapply each year if your income changes. The income limit is set by New York State and updated each year. The application goes through the state, but the county’s assessment records show the credit once it is approved.
Veterans and Other Exemptions
Nassau County offers exemptions for veterans who served during wartime, for their spouses, and for people with disabilities. The amounts vary based on the type of service and the level of disability. Clergy and volunteer firefighters may also qualify for partial exemptions. These are applied to the county portion of the tax bill, not the school tax.
How to Pay Your Property Tax Bill
The county mails tax bills once a year, in late December or early January. The bill covers the full year of taxes, but you can pay it in two halves. The first half is due by the end of January. The second half is due by the end of May or the beginning of June, depending on the year.
Ways to Pay Your Bill
You can pay online through MyNassauTax.com with a bank account or credit card. You can pay by mail with a check or money order. You can also pay in person at the Treasurer’s Office in Mineola. Some banks and credit unions also accept county tax payments for free.
Deadlines and Late Fees
If your payment arrives after the due date, the county adds interest. Interest starts at a low rate and grows each month the bill stays unpaid. If the bill stays unpaid for years, the county can place a lien on the property and may sell the lien to a private buyer. Paying on time protects you from extra costs and protects your home from liens.
Filing a Tax Grievance in Nassau County
If you think your home is worth more on the tax roll than it would sell for, you can file a grievance. A grievance is a formal request to lower the assessed value. The county runs a special board each year to hear these requests, called the Assessment Review Commission or the Board of Assessment Review.
Who Can File and When
Any property owner can file a grievance. You must file between March 1 and the deadline set by the county, which is usually in early June. The form is available on the Department of Assessment website. You can file online, by mail, or in person. There is no fee to file.
How the Grievance Process Works
After you file, the Department of Assessment reviews your claim. They may agree and lower the value, or they may reject the claim. If you disagree with their decision, you can ask for a hearing before the board. At the hearing, you present evidence, like recent sales of similar homes in your area. The board then makes a final ruling. Most hearings take less than 30 minutes.
Public Access to Tax Records
New York State law makes property tax records public. This means anyone can ask to see them. The county must share the data unless the law blocks the release for a specific reason, like a protected address for a police officer or domestic violence survivor.
What Records Anyone Can See
The owner’s name, the property address, the assessed value, the lot size, and the tax bill are all public. Past sales prices are also public. Anyone can ask for a copy of the property record card, which shows the full data the assessor used to set the value. You can also get bulk data from the county for research, but you must pay a small fee for large data sets.
Contact Offices and Locations
Two county offices handle property tax records. Both are open to the public during normal business hours on weekdays. Most services are also available online at any time of day.
Department of Assessment
The Nassau County Department of Assessment is the office that sets property values and handles grievances. The main office is at 240 Old Country Road, Mineola, NY 11501. The phone number is (516) 571-1500. Office hours are Monday through Friday, 9:00 a.m. to 4:45 p.m. The official website is www.nassaucountyny.gov. The Assessment Department is open to walk-ins who want to review their property record card or file a grievance in person.
Treasurer’s Office
The Nassau County Treasurer’s Office handles tax billing, payments, and liens. The office is located at 1 West Street, Mineola, NY 11501. The phone number is (516) 571-6100. Office hours are Monday through Friday, 9:00 a.m. to 4:00 p.m. The official website is www.nassaucountyny.gov/agencies/treasurer. The Treasurer’s Office also runs the MyNassauTax.com portal where you can view bills and pay online.
Frequently Asked Questions
Many people have similar questions about Nassau County property tax records. The answers below cover the most common issues, from basic lookups to appeals. Each answer uses current 2026 county rules and state law. If your question goes beyond these basics, call the county offices listed above during business hours.
How Do I Look Up a Tax Bill by Address?
Go to MyNassauTax.com and type the full street address into the search bar. The site pulls up the parcel, shows the current amount owed, and lists past payments. You can also download a PDF copy of the latest bill. The system is free and works without an account. If the address is very new and not in the system yet, wait until the next tax bill is issued or call the Treasurer’s Office for a manual lookup.
Can I See Nassau County Tax Records for Free?
Yes. Basic lookups by address, parcel number, or owner name are free on MyNassauTax.com. Printed copies of property record cards are also free when you ask in person at the Department of Assessment. Bulk data downloads for researchers or businesses may carry a small fee set by the county. The county does not charge for viewing any record in person at the counter.
What Is a Section Block Lot Number in Nassau County?
A Section, Block, and Lot number, or SBL, is the county’s way of giving each parcel a unique ID. The section is a large area, the block is a smaller group, and the lot is the single property. The full number looks like 49-225-123. You can find your SBL on any tax bill, on a deed, or by looking up your address on the county portal. Lenders and title companies use the SBL to track property records.
How Long Do I Have to Appeal My Assessment?
You must file a grievance application by the deadline set by the county each year. The deadline is usually in late May or early June, but the exact date changes. The Department of Assessment posts the date on its website as soon as the tentative roll is published in May. Late applications are not accepted. If you miss the window, you must wait for the next tax year to file again.
What Happens If I Do Not Pay My Property Tax?
Unpaid taxes grow interest and penalties each month. After several years of non-payment, the county can place a tax lien on your property. The lien can then be sold to a private investor, who pays the tax bill and collects the amount from you, plus interest. In rare cases, the county can foreclose on the home. Paying even a small part of the bill each year stops the lien process from starting.
Are Property Tax Records Public for All Owners in New York?
Most records are public under New York’s Freedom of Information Law. You can see the owner’s name, address, assessed value, and tax status. A few records are private, such as the home address of judges, police officers, and domestic violence survivors who have filed for address protection. For all other owners, the data is open to anyone who asks.
Can I View Nassau County Tax Records From Other States?
Yes. The MyNassauTax.com portal works from any computer or phone with internet access, no matter where you live. Out-of-state landlords, heirs, and buyers often look up Nassau County records this way. You can also request records by mail by sending a written request to the Department of Assessment with the parcel number or address and a self-addressed stamped envelope.