NASSAU COUNTY HOMEOWNER RESOURCES
Filing your grievance online with Nassau County ARC
Filing with the Assessment Review Commission is free and designed for homeowners to do themselves. Most of the work happens before you open the form.
The County publishes its own filing instructions, and they take precedence over this page. Read Nassau County’s appeal instructions first, then use this guide to prepare.
Before you open the form
Gather these so you are not hunting for them with the window closing:
- Your County record. The parcel identifier — section, block, and lot as the County records them — plus the assessment year you are appealing and the market and assessed values shown. Our property checker is a starting point; confirm with the County’s own record.
- The owner’s name as recorded. The application is made by the owner or by someone the owner authorizes, so know which of those you are and whether anyone else already has an authorization for this year.
- Your view of the value, and why. Expect to be asked what you believe the property is worth. Our comparable sales guide covers how to support that figure honestly.
- Supporting documents as files. An appraisal, photographs, a recent sale contract, an inspection report, or permits, in a format you can upload if the County’s system asks for attachments.
- An email address you check. If the system offers to send confirmations electronically, you want them to arrive somewhere you will see.
Common questions
Is there a fee to file a grievance online with Nassau County ARC?
No. Nassau County states there is no fee to file with the Assessment Review Commission, and that you are not required to use an attorney. The published filing window for the 2028–29 assessment year is January 4–March 1, 2027.
Confirm the dates and current instructions on Nassau County’s appeal instructions. A firm’s fee for filing on your behalf is a separate commercial arrangement; Good Grieves charges a flat $200 service fee with no percentage of your tax savings.
What is AROW?
AROW is the name Nassau County uses for its online assessment-appeal filing system. The County’s appeal instructions link to it, and a completed online filing returns an appeal number or confirmation that you should keep.
Start from the County’s instructions page rather than from a search result, so you reach the County’s own system for the current cycle.
What is form AR1?
AR1 is the County’s application form for residential property owners appealing their assessment. Other property types use different applications. The County’s form instructions say which application applies to your property and what it requires.
Do not fill in a prior year’s form from memory. Open the current instructions on the County’s page and use the application it provides for the assessment year you are appealing.
What confirmation should I keep?
Keep the appeal number or confirmation the online system returns, any email it sends, and a copy of everything you submitted, including attachments. Until you have that confirmation, nothing has been filed.
Store the confirmation with your labeled record and your evidence. If you later pursue Small Claims Assessment Review, you will want the appeal number and the dates close at hand.
The filing, in general terms
The County does not need us to reproduce its screens, and we do not try to. In outline, an online filing means: reaching the County’s system from its instructions page; identifying your property so the application attaches to the right record; completing the application for your property type, including the value you are asking the County to consider; attaching support where the system allows it; and submitting. The application is your statement about your own property, so read it once more before you submit rather than after.
Where the County’s instructions describe a step differently from this outline, follow the County. Its page is updated for each cycle; this page is general.
Representatives and duplicate filings
You can file for yourself or authorize a representative to file for you — not both. Duplicate applications and overlapping authorizations create avoidable problems, so if a firm, a prior owner, or a condominium board may already be filing for this assessment year, settle that first. The County’s instructions cover both routes. If your property is assessed by a village or city, that assessment has a separate local appeal process, which the County FAQ explains.
After you submit
ARC will either reduce your assessment or leave it unchanged; the County states it will never increase the assessment. Our guide on whether filing can raise your assessment quotes the County’s wording. Keep your confirmation, the labeled record you filed against, and your evidence together. If ARC’s outcome does not satisfy you, Small Claims Assessment Review is the optional next step, with its own fee and a short deadline.
Good Grieves does not file applications with the County through this website, does not authorize representation, and does not guarantee savings. This page is general information, not legal advice.
Keep reading
Nassau County tax grievance deadline
The published 2027 filing window, a preparation checklist, and where to confirm current instructions.
Choosing comparable sales
Which nearby sales support an appeal, which differences matter, and why a neighbor’s lower bill is not evidence.
See how it applies to your home
Review your available County record alongside what you’ve learned.
Check my property