Trusted by 100+ across Nassau County

We Slash Your Nassau County Property Tax Bill by Thousands – In Minutes.

You don’t pay us a dime unless we save you money… (80% Success Rate)

Get Started

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Left To Appeal Your Assessment

(Grievances for this tax year have to be filed with Nassau County by March 2nd, 2026. After this deadline you will not be able to file an appeal until 2027.)

Benefits of Working with Us:

No Savings, No Fee

No Savings,

No Fee

Done by a Long Island CPA with 6+ Years of Experience

No Risk of Assessment Increase when you appeal

80% Success Rate

Not Time Consuming At All - We handle everything

Don't let another year go by without fighting your property tax assessment

Nassau County has the 2nd highest property taxes in America

80% of homeowners who appeal, WIN.

Big firms take half your refund (50%) when they win. We take 33%.

Miss the March 2nd deadline, and you're stuck paying too much for another year

Yes, I want lower property taxes

Here is how we will help you fix this in 3 simple steps:

Step 1:

Fill out the short form (This takes 1 minute)

Step 2:

Sign the short authorization form we email you

Step 3:

We handle everything else:

Analyze comparable properties in your neighborhood
File all paperwork before the March 2nd deadline
Advise you on whether to accept their offer or appeal further

Analyze comparable properties in your neighborhood
File all paperwork before the March 2nd deadline
Advise you on whether to accept their offer or appeal further

End Result:

Most of our clients save thousands of dollars on their next property tax bill.

We charge a one-time fee of 33% of the tax we save you. You only pay us when you accept the county’s offer. No Savings = No Fee.

Most of our clients save thousands of dollars on their next property tax bill.

We charge a one-time fee of 33% of the tax we save you. You only pay us when you accept the county’s offer. No Savings = No Fee.

file Grievances before March 2nd

About Andrew Donnelly, CPA

Born and raised on Long Island. Nearly a decade helping Nassau County homeowners save thousands in property taxes.

Unlike high-volume firms, you get direct access to a local CPA who understands Nassau County's assessment system inside and out.

Born and raised on Long Island. Nearly a decade helping Nassau County homeowners save thousands in property taxes.

Unlike high-volume firms, you get direct access to a local CPA who understands Nassau County's assessment system inside and out.

Deadline: March 2nd, 2026

After March 2nd, you're locked in for another year at your current assessed value.

This takes 2 minutes. There's zero risk. And you could save thousands.

Questions? Call or text: (516) 508-3645

(No fee to start. No fee if we don't save you money. 33% only when we win.)

FAQs

Will anyone from the county come and inspect my property?

Is there any risk my taxes could go up if I grieve?

How often should I file a property tax assessment?

What if I miss the deadline?

How long does the process take from start to finish?

Can I grieve the assessment on my rental property?

Nassau Property Tax Advisors LLC and Donnelly Accounting & Advisory LLC are private companies and are not affiliated with, endorsed by, or acting on behalf of Nassau County, the Nassau County Department of Assessment, or the Nassau County Assessment Review Commission (ARC). We are not a law firm and do not provide legal or tax advice through this website. Information provided is for general informational purposes only. Outcomes, assessment reductions, and tax savings are not guaranteed and depend on the County’s review and determination and the specific facts of your property. Prior results do not guarantee a similar outcome. By submitting your information, you consent to be contacted by phone, email, and/or text regarding your request. Msg & data rates may apply. Opt out anytime.

andrew@nassaupropertytaxadvisors.com

(516) 508-3645