AppealDesk

Warren County Property Tax Appeal — New Jersey

Rob HartleyRob Hartley·Updated March 5, 2026

Warren County is located in northwestern New Jersey with a population of approximately 109,632 residents as of the 2020 census. The county seat is Belvidere, with major population centers including Phillipsburg (the largest municipality with over 15,000 residents), Hackettstown, and Washington. Property tax appeals are particularly important in Warren County given its high tax burden—the median property tax bill of $5,907 annually ranks the county 21st highest among all 3,143 U.S. counties. Warren County's median home value of $307,300 is slightly below the New Jersey median, yet homeowners here pay an effective tax rate of 1.92%, which is above the national median rate of 0.89%.

Notable cities: Phillipsburg, Hackettstown, Belvidere, Washington

Median Home

$307,300

Tax Rate

1.92%

Annual Tax

$5,907

Population

109,632

2026 Appeal Deadline: April 1, 2026, or 45 days from the date assessment notices are mailed, whichever is later

For Warren County, the standard appeal deadline is April 1 of the tax year or 45 days from the bulk mailing date of assessment notices (typically mid-April), whichever is later. In municipalities that have undergone a revaluation or reassessment, the deadline extends to May 1, 2026, or 45 days from notice mailing. Filing deadlines are strictly enforced with no extensions except for extraordinary circumstances.

Property in Warren County, New Jersey — local tax assessment and appeal guide

How Warren County Assesses Property

100%of market value

Assessed by: Warren County Board of Taxation

Assessment cycle: annual

Notices typically mailed: mid-April (spring)

In Warren County, New Jersey requires all real property to be assessed at 100% of its market value. This means your assessed value equals your property's full market value. For example, if your home's market value is $307,300 (the county median), at New Jersey's 100% assessment ratio your assessed value would be $307,300, resulting in approximately $5,900 in annual taxes at the county's effective rate of 1.92%.

The Appeal Process

Appeals are heard by the Warren County Board of Taxation. After filing your appeal, the Warren County Board of Taxation will schedule a hearing, typically between late April and early June. You'll have 5-15 minutes to present your evidence to the Board members, who will review comparable sales, property conditions, and other documentation. The Board will issue a written decision within 2-4 weeks of your hearing.

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Step 1: Review your assessment notice received in mid-April and compare your assessed value to recent sales of comparable properties in your area.

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Step 2: Contact your municipal tax assessor for an informal review or discussion if you believe your assessment is incorrect. Many issues can be resolved at this stage without filing a formal appeal.

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Step 3: Gather evidence including comparable property sales (Form A-1 Comp. Sale), photographs of property condition issues, recent appraisals, and repair estimates that support your claim of overassessment.

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Step 4: Complete Form A-1 (Petition of Appeal) and submit it with your evidence and the $25 filing fee to the Warren County Board of Taxation before the April 1 deadline (or 45 days from notice mailing, whichever is later).

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Step 5: Attend your hearing before the Warren County Board of Taxation (typically scheduled between late April and early June) and present your evidence in a clear, factual manner.

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Step 6: If the County Board's decision is unsatisfactory, you may appeal to the New Jersey Tax Court within 45 days of the Board's judgment. For properties assessed over $1,000,000, you have the option to file directly with Tax Court initially.

Required form: Form A-1 (Petition of Appeal) and Form A-1 Comp. Sale

Filing Methods

mail:Warren County Board of Taxation, 202 Mansfield Street, Belvidere, NJ 07823
in-person:Warren County Board of Taxation, Cummins Building, 202 Mansfield Street, Belvidere, NJ 07823
online:Available through New Jersey online appeal filing system at njappealonline.com (check with county for availability)

Evidence to Bring

Comparable property sales (3-5 similar properties that sold for less than your assessed value)Photographs documenting property condition issues or defectsProfessional appraisal reports (appraiser must appear at hearing if submitted)Repair estimates or contractor quotes for needed workProperty tax records showing assessment disparities with similar homes

Warren County Assessor Contact

Warren County Board of Taxation

Phone: (908) 475-6070

Address: Cummins Building, 202 Mansfield Street, Belvidere, NJ 07823

Website: https://www.warrencountynj.gov/government/tax-board

Online Portal: https://secure.njappealonline.com

Hours: Meetings held second Thursday of each month at 10:00 AM

Tax Exemptions in Warren County

Senior Citizen and Disabled Persons Property Tax Deduction

$250 annual deduction

Annual $250 deduction from property taxes for qualified senior citizens age 65+ or disabled persons who meet income requirements.

Eligibility: Must be age 65 or older, or receiving Social Security disability; own and occupy the property as principal residence; New Jersey resident; total income less Social Security or government pension cannot exceed $10,000 annually.Deadline: December 31 annually (eligibility determined as of October 1 of prior year)

Veteran Property Tax Deduction

$250 annual deduction

Annual $250 deduction from property taxes for honorably discharged veterans who served during wartime or qualifying peacekeeping missions.

Eligibility: Honorably discharged from active duty service in U.S. Armed Forces during wartime; must own property and be a legal New Jersey resident; surviving spouses eligible if unremarried and meet residency requirements.Deadline: December 31 annually (eligibility determined as of October 1 of prior year)

100% Disabled Veteran Property Tax Exemption

100% exemption (full property tax exemption)

Complete property tax exemption on dwelling house and lot for veterans with 100% permanent and total service-connected disability.

Eligibility: Honorably discharged veteran with VA certification of 100% permanent and total service-connected disability; must own and occupy dwelling as principal residence; New Jersey resident; surviving spouses of eligible veterans also qualify if unremarried.Deadline: File Form D.V.S.S.E. with municipal tax assessor; can appeal denial by April 1 of following year

Official Resources

Warren County Board of Taxation Official Website →

Official county tax board website with appeal information, meeting schedules, and contact details for filing property tax appeals.

New Jersey Division of Taxation - Property Tax Appeals →

State resource explaining the property tax appeal process, required forms, deadlines, and guidance for New Jersey homeowners.

New Jersey Online Appeal Filing System →

Online portal for filing property tax appeals electronically with participating New Jersey county boards of taxation.

NJ Property Tax Deductions and Exemptions →

Comprehensive information on available property tax deductions including senior, veteran, and disabled veteran exemptions with application forms and eligibility requirements.

Warren County Appeal Statistics

Success Rate

40-60% (typical for New Jersey)

Avg Reduction

$NaN

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Frequently Asked Questions

What is the deadline to appeal my property taxes in Warren County for 2026?
The deadline to file a property tax appeal in Warren County is April 1, 2026, or 45 days from the date assessment notices are bulk mailed (typically mid-April), whichever is later. For municipalities that underwent a revaluation or reassessment, the deadline extends to May 1, 2026, or 45 days from notice mailing. These deadlines are strictly enforced, and missing them means you must wait until the following year to appeal. There are no extensions except for extraordinary circumstances such as medical emergencies or death in the family, which require documentation.
How do I file a property tax appeal online in Warren County?
Warren County participates in New Jersey's online appeal filing system available at njappealonline.com. You'll need to create an account, complete Form A-1 (Petition of Appeal), upload your comparable sales evidence using Form A-1 Comp. Sale, and pay the $25 filing fee electronically. Alternatively, you can file by mail or in person at the Warren County Board of Taxation, Cummins Building, 202 Mansfield Street, Belvidere, NJ 07823. Make sure to file before the April 1 deadline or within 45 days of receiving your assessment notice, whichever is later.
What happens at a Warren County Board of Taxation hearing?
After you file your appeal, the Warren County Board of Taxation will schedule a hearing typically between late April and early June. You'll have approximately 5-15 minutes to present your case to the Board members. Bring your evidence including comparable property sales, photographs, appraisals, and any documentation showing your property is overassessed. The Board will review your evidence and may ask questions about your property. The municipality may also present their assessment defense. Within 2-4 weeks of the hearing, you'll receive a written decision by mail either granting a reduction, denying your appeal, or maintaining your current assessment.
How much can I save by appealing my property taxes in Warren County?
Successful property tax appeals in Warren County typically result in an 8-20% reduction in assessed value. For a home assessed at the county median of $307,300, that translates to a reduction of $24,584 to $61,460 in assessed value, saving you approximately $472 to $1,180 annually at the county's 1.92% effective tax rate. Over 10 years, that's $4,720 to $11,800 in total savings. Success rates in New Jersey range from 40-60%, meaning nearly half of homeowners who appeal receive some tax relief. The actual savings depend on the strength of your evidence and how much your property is overassessed.
What evidence do I need for a successful Warren County property tax appeal?
To win your Warren County property tax appeal, you need objective evidence that your property is overvalued. The most compelling evidence includes 3-5 comparable property sales from the past 6-12 months that sold for less than your assessed value—these should be similar in size, age, condition, and location. You should also provide photographs documenting any property defects, needed repairs, or unfavorable conditions. Professional appraisals carry significant weight, but if you submit one, both you and the appraiser must appear at the hearing. Additionally, bring repair estimates, contractor quotes for needed work, and property tax records showing how your assessment compares to similar neighboring homes. Submit all evidence with your Form A-1 filing when possible.
What is the veteran and senior citizen property tax deduction worth in Warren County?
Warren County offers two $250 annual property tax deductions: one for qualified veterans and one for senior citizens or disabled persons. Veterans must be honorably discharged and have served during wartime to qualify, while senior citizens must be age 65 or older with income (excluding Social Security) not exceeding $10,000 annually. Both exemptions require that you own and occupy the property as your principal residence and be a New Jersey resident. Applications must be filed with your municipal tax assessor by December 31 each year, with eligibility determined as of October 1 of the prior year. Additionally, veterans with 100% permanent service-connected disability may qualify for a complete property tax exemption on their primary residence.
Can I discuss my assessment with the Warren County assessor before filing an appeal?
Yes, absolutely. Before filing a formal appeal with the Warren County Board of Taxation, you should contact your municipal tax assessor to discuss your assessment during an informal review. Many tax assessors hold informal meetings where you can review your property data for accuracy—checking square footage, number of rooms, property features, and overall condition. If the assessor finds errors in their records, they may correct your assessment without requiring a formal appeal, saving you time and the $25 filing fee. This informal process is completely separate from the formal appeal process. If you remain unsatisfied after the informal review, you can still file a formal Petition of Appeal (Form A-1) with the County Board of Taxation by the April 1 deadline.
What is Warren County's assessment ratio and how does it affect my property taxes?
Warren County assesses all properties at 100% of market value, as required by New Jersey law. This means your assessed value should equal your property's full and fair market value. Unlike some states that use fractional assessment ratios, there's no multiplication factor in Warren County—what your property could sell for on the open market is what it should be assessed at for tax purposes. This 100% ratio makes it easier to compare your assessment to recent home sales in your neighborhood. If comparable homes are selling for significantly less than your assessed value, you have strong grounds for a property tax appeal. The county determines market value as of October 1 of the pretax year by analyzing recent sales, property characteristics, and market conditions.

For state-wide appeal information including New Jersey's assessment ratio and deadlines, see our New Jersey Property Tax Appeal Guide →

Considering professional help with your appeal? Compare pricing, coverage, and pros/cons in our Best Property Tax Appeal Services (2026) or browse side-by-side service comparisons →

More New Jersey Counties

Atlantic County (Atlantic City)Bergen County (Hackensack)Burlington County (Mount Holly)Camden County (Camden)Cape May County (Ocean City)Cumberland County (Bridgeton)
← All New Jersey property tax appeal info

Sources: https://www.warrencountynj.gov/government/tax-board | https://www.nj.gov/treasury/taxation/lpt/lpt-appeal.shtml | https://www.tax-rates.org/new_jersey/warren_county_property_tax | https://en.wikipedia.org/wiki/Warren_County,_New_Jersey | https://www.nj.gov/treasury/taxation/lpt/lpt-deductions.shtml

Last verified: 2026-03-05