1. Check your assessment
We compare the County's valuation against Nassau property records, recent sales, and neighborhood assessment patterns to identify possible over-assessment signals.
What FairValue does
FairValue turns Nassau assessment data into filing-ready evidence.
FairValue helps Nassau County homeowners check whether their property may be over-assessed, understand the evidence behind the estimate, and choose the right filing path: a DIY evidence pack or full-service grievance support.
2. Build the evidence
We organize comparable sales, equity comparisons, and property-specific facts into a clearer valuation argument that can support a grievance filing.
3. Choose your filing path
File yourself with a DIY Evidence Pack, or use full-service support if the estimated savings signal is strong enough to justify done-for-you help.
Instant assessment review for Nassau County homes
DIY Evidence Pack from $99 early bird or $149 regular
Full-service option with $0 upfront and 25% early bird or 30% regular success fee
Built around the 2027 grievance cycle for 2028/29 tax bills
Why file annually?
In Nassau County, each assessment roll is a new valuation cycle. A prior reduction may help, but it does not guarantee that your next assessment is still fair. Filing annually helps preserve your opportunity to challenge the current roll before the deadline closes.
Each roll is a new case
The tentative assessment roll is published on January 2, 2027. That new value controls the 2028/29 challenge cycle, even if you filed in a prior year.
Your evidence changes
Recent sales, comparable homes, and neighborhood equity patterns can shift year to year. Current evidence is usually stronger than relying on last year’s argument.
Skipping can cost a year
The next filing deadline has not yet been announced. Once the annual grievance window closes, homeowners generally lose the chance to challenge that year’s assessment.
Sample evidence report
Better evidence makes the appeal easier to understand.
FairValue organizes your appeal around the facts ARC reviewers need to see: the County's valuation, comparable sales, neighborhood assessment patterns, and property-specific conditions that may support a lower value.
Comparable sales review
The report compares your home against relevant nearby sales, helping show whether the County's market value is higher than recent evidence supports.
Neighborhood equity analysis
FairValue checks whether similar nearby homes appear assessed more favorably, turning local assessment patterns into a clearer grievance argument.
Property condition adjustments
If your home has documented defects or deferred maintenance, the report can explain why those conditions may reduce value compared with renovated peer properties.
Why this is stronger than a generic appeal
Instead of submitting a loose claim that taxes feel too high, FairValue structures the appeal as a valuation record: what the County says, what the market suggests, how nearby homes compare, and what property-specific facts may justify an adjustment.
Read common filing questionsEvidence pack preview
Nassau County assessment challenge
- Nassau County parcel and assessment context
- Recent comparable sales filtered for local relevance
- Assessment equity checks against similar nearby homes
- Repair issues and outdated features factored into your home value
- Plain-English grievance narrative for ARC review
- DIY filing guidance or full-service follow-through
Local Nassau coverage
Browse by town and school district
Explore Nassau property tax appeal opportunities by local area and school district.
Nassau area hubs
GREAT NECK672 high-priority propertiesMANHASSET592 high-priority propertiesPORT WASHINGTON475 high-priority propertiesSYOSSET355 high-priority propertiesROSLYN332 high-priority propertiesROCKVILLE CENTRE297 high-priority propertiesJERICHO272 high-priority propertiesGLEN HEAD220 high-priority properties
School district hubs
Great Neck Public Schools718 propertiesSyosset Central School District597 propertiesPort Washington Union Free School District572 propertiesManhasset Union Free School District509 propertiesJericho Union Free School District378 propertiesRoslyn Union Free School District336 propertiesLocust Valley Central School District308 propertiesHewlett-Woodmere Union Free School District266 properties
Browse all school districtsFrequently asked questions
These are the questions Nassau homeowners usually ask before deciding whether to file a grievance.
What does FairValue do?
FairValue analyzes Nassau County assessment records, comparable sales, neighborhood equity data, and property details to help homeowners decide whether a property tax grievance is worth filing.
Can my assessment go up if I file?
No. In Nassau County, the Assessment Review Commission cannot increase your assessment because you filed a grievance. The result is either a reduction or no change.
Do I need a lawyer?
No. Homeowners can file through Nassau County ARC themselves. FairValue offers a flat-fee DIY evidence pack and a managed full-service option for owners who want help with the process.
When is the Nassau grievance deadline?
The 2027 filing window begins when the tentative roll is published on January 2, 2027. The current deadline display is Not yet announced.