AppealDesk

Mercer County Property Tax Appeal — New Jersey

Rob HartleyRob Hartley·Updated March 5, 2026

Mercer County is located in Central New Jersey with Trenton as its county seat and state capital, earning it the nickname 'The Capital County.' As of 2020, the county had a population of 387,340, making it the state's 12th-most-populous county. Property tax appeals are particularly important in Mercer County due to its significantly high tax burden—the county ranks 17th highest among 3,143 U.S. counties for median property taxes. The median annual property tax bill of $7,200 is $4,800 higher than the national median of $2,400, making professional assessment reviews critical for homeowners seeking relief from excessive valuations.

Notable cities: Trenton, Princeton, Hamilton Township, Ewing Township, Lawrence Township

Median Home

$309,300

Tax Rate

2.02%

Annual Tax

$6,245

Population

397,980 (2025 estimate)

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

Appeals must be filed with the Mercer County Board of Taxation on or before April 1 of the tax year or within 45 days from the date that Assessment Notification postcards are mailed by the municipality, whichever is later. Assessment notices are mailed at the end of January each year. For added or omitted assessments, the deadline is December 1 or 30 days from bulk mailing of tax bills, whichever is later. If the deadline falls on a weekend or holiday, it extends to the next business day.

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

How Mercer County Assesses Property

100%of market value

Assessed by: Municipal Tax Assessors (supervised by Mercer County Board of Taxation)

Assessment cycle: annual

Notices typically mailed: Late January (typically end of January)

In Mercer County, properties are assessed at 100% of their true market value, meaning your assessed value equals your property's market value. For example, if your home's market value is $309,300 (the county median), at New Jersey's 100% assessment ratio your assessed value would be $309,300, resulting in approximately $6,245 in annual taxes at the county's effective rate of 2.02%. This one-to-one ratio simplifies the relationship between market value and assessment, making it easier to determine if you're being overassessed by comparing recent comparable sales directly to your assessment.

The Appeal Process

Appeals are heard by the County Board of Taxation. Tax appeal hearings are held after the April 1 deadline, scheduled during weekdays starting at 9 a.m. Adjournments are generally denied, so attendance is critical. You must prove your assessment is unreasonable compared to market value, overcoming the legal presumption that your current assessment is correct.

1

Review your Tax Assessment Notice Postcard received in late January to verify your assessment information is correct and compare it to recent comparable sales in your neighborhood.

2

Gather evidence including 3-5 comparable sales of similar properties in your area, photos of property condition issues, repair estimates for defects, and recent appraisals. Any evidence must be submitted at least seven days prior to your hearing.

3

Complete and file the Petition of Appeal form with the Mercer County Board of Taxation on or before April 1 (or within 45 days of receiving your assessment notice, whichever is later), serving copies to both the Municipal Assessor and Municipal Clerk.

4

Attend the informal hearing scheduled by the County Board of Taxation, typically held after the April 1 deadline during weekdays starting at 9 a.m. Present your evidence proving your assessment exceeds market value by at least 15% of the common level. Missing your hearing without postponement results in dismissal.

5

Receive the Board's judgment. If your appeal is successful, your assessment will be reduced. If denied, you can appeal to the New Jersey Tax Court by filing within the statutory deadline, typically by April 1 of the following year or as directed in the Board's decision.

6

For properties assessed over $1,000,000, you have the option to bypass the County Board and file directly with the New Jersey Tax Court by the same April 1 deadline or within 45 days of receiving your assessment notice.

Required form: Petition of Appeal (Form available from Mercer County Board of Taxation)

Filing Methods

mail:Mercer County Board of Taxation, 640 South Broad Street, Room 317, Trenton, NJ 08611. One copy must also be served on the Municipal Assessor and Municipal Clerk.
in-person:McDade Administration Building, 640 South Broad Street, Room 317, Trenton, NJ 08650. Forms also available at Municipal Assessor's office.
phone:Call (609) 989-6704 to request forms by telephone. Faxes and email copies will not be accepted for filing.

Evidence to Bring

Comparable sales (3-5 similar properties)Property condition photosRepair estimates for defectsRecent appraisal (if available)Income/expense statements (for commercial properties)

Mercer County Assessor Contact

Mercer County Board of Taxation

Phone: (609) 989-6704

Address: McDade Administration Building, 640 South Broad Street, Room 317, Trenton, NJ 08650

Website: https://www.mercercounty.org/government/board-of-taxation

Online Portal: http://pip.mercercounty.org

Hours: Monday-Friday, 8:30 AM - 4:30 PM

Tax Exemptions in Mercer County

Senior Citizen/Disabled Person Deduction

$250

Annual deduction from property taxes for qualified homeowners

Eligibility: Age 65 or older, or permanently and totally disabled, with annual income not exceeding $10,000 (excluding Social Security, pensions, and retirement benefits). Must be a New Jersey resident for one year prior to October 1 of the pre-tax year and own and occupy the dwelling as principal residence.Deadline: October 1 of the pre-tax year (initial application); March 1 (annual post-tax year income statement)

Veteran's Deduction

$250

Annual property tax deduction for qualified veterans or surviving spouses

Eligibility: Honorably discharged veterans who had active duty service in the U.S. Armed Forces, or unmarried surviving spouse. Must be a New Jersey resident and property owner. No wartime service requirement as of December 4, 2020.Deadline: File with municipal tax assessor (no specific deadline, can apply anytime during tax year)

100% Disabled Veteran Property Tax Exemption

100% of property taxes (full exemption)

Full exemption from property taxes on principal residence

Eligibility: Honorably discharged veterans who are 100% permanently and totally disabled from service-connected disabilities certified by the U.S. Department of Veterans Affairs, or unmarried surviving spouses of such veterans. Must own and occupy dwelling as principal residence and be New Jersey resident.Deadline: File Form D.V.S.S.E. with municipal tax assessor at any time during tax year; partial/prorated exemption available from date of acquisition

Official Resources

Mercer County Board of Taxation Official Website →

Access appeal forms, instructions, brochures, and contact information for filing property tax appeals in Mercer County.

Mercer County Property Information Portal (PIP) →

Search property records, assessments, sales data, deeds, and tax information for properties throughout Mercer County.

NJ Division of Taxation - Property Tax Information →

Official New Jersey state resource for property tax programs, exemptions, deductions, appeals guidance, and forms for homeowners and veterans.

NJ Property Tax Deduction and Exemption Forms →

Download official state forms for senior citizen deductions, disabled veteran exemptions, and other property tax relief programs available in New Jersey.

Check Your Mercer County Assessment

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Frequently Asked Questions

What is the deadline to appeal my property taxes in Mercer County for 2026?
The deadline to file a property tax appeal in Mercer County is April 1, 2026, or within 45 days from the date your Assessment Notification postcard is mailed by your municipality, whichever is later. Since assessment notices are typically mailed at the end of January, most homeowners face the April 1 deadline. If April 1 falls on a weekend or legal holiday, the deadline extends to the first succeeding business day. For added or omitted assessments, a separate December 1 deadline applies. Missing these deadlines means you cannot appeal for that tax year.
How do I file a property tax appeal with the Mercer County Board of Taxation?
To file an appeal, obtain a Petition of Appeal form from the Mercer County Board of Taxation by calling (609) 989-6704, downloading it from their website, visiting their office at 640 South Broad Street Room 317 in Trenton, or requesting it from your Municipal Assessor. Complete the form and file one copy with the County Board of Taxation and serve one copy each to your Municipal Assessor and Municipal Clerk by the April 1 deadline. Email and fax submissions are not accepted. Include a list of 3-5 comparable sales with your petition, and submit all evidence at least seven days before your scheduled hearing.
What evidence do I need to win my property tax appeal in Mercer County?
The most credible evidence is 3-5 comparable sales of similar properties in your neighborhood that sold recently. You must prove your assessment exceeds your property's true market value and is at least 15% above the common level. Additional supporting evidence includes photographs documenting property defects or deterioration, professional appraisals, repair estimates for structural issues, and income/expense statements for commercial properties. All evidence must be submitted to the Municipal Assessor and Mercer County Board of Taxation (5 copies) at least seven days prior to your hearing. Remember, your current assessment is presumed correct by law, so you bear the burden of proof.
What happens at a Mercer County Board of Taxation hearing?
Tax appeal hearings are scheduled during weekdays starting at 9 a.m. after the April 1 filing deadline. You must attend your hearing in person as adjournments are generally denied. During the hearing, you'll present your evidence proving your assessment is unreasonable compared to market value standards. The Board will review your comparable sales, photos, and other documentation. If you miss your hearing without obtaining a postponement, your case will be dismissed 'for lack of prosecution' and this dismissal is final for the current year with no further appeal to Tax Court. The Board will issue a judgment either reducing your assessment, maintaining it, or potentially increasing it if you're under-assessed.
How much can I save by appealing my property taxes in Mercer County?
Savings depend on how much your assessment is reduced. With Mercer County's 2.02% effective tax rate and $6,245 median tax bill, every $10,000 reduction in assessed value saves approximately $202 annually. For example, if you successfully reduce your assessment from $350,000 to $320,000 (a $30,000 reduction), you'd save about $606 per year. Research shows that about 25% of homes nationwide are over-assessed, paying an average of $1,346 too much annually. Given that Mercer County has some of the highest property taxes in the nation, successful appeals can result in substantial long-term savings, especially considering the reduction typically applies to future years until the next revaluation.
Can I appeal my Mercer County property taxes online?
No, Mercer County does not accept property tax appeals filed electronically. According to the County Board of Taxation, faxes and email copies will not be accepted for filing appeals. You must file your Petition of Appeal in person at the McDade Administration Building at 640 South Broad Street, Room 317 in Trenton, or mail it with copies served on your Municipal Assessor and Municipal Clerk. You can download the appeal forms from the county website at mercercounty.org/government/board-of-taxation, but the completed forms must be physically delivered or mailed. For questions about the process, call the Board at (609) 989-6704.
What is the Senior Citizen property tax deduction worth in Mercer County?
The Senior Citizen/Disabled Person deduction in Mercer County provides an annual $250 reduction from your property tax bill. To qualify, you must be age 65 or older (or permanently disabled) as of December 31 of the pre-tax year, been a New Jersey resident for at least one year prior to October 1 of the pre-tax year, and have annual income not exceeding $10,000 (excluding Social Security, pensions, and retirement benefits). You must own and occupy the property as your principal residence. Apply with your municipal tax assessor before October 1, and file an annual Post-Tax Year Income Statement by March 1 to continue receiving the benefit.
Can I appeal directly to Tax Court instead of the County Board in Mercer County?
Yes, but only under certain circumstances. If your property's assessed valuation exceeds $1,000,000, you may bypass the Mercer County Board of Taxation and file a petition of appeal (called a Local Property Tax Complaint) directly with the New Jersey Tax Court. The deadline is the same: April 1 of the tax year or within 45 days from when assessment notifications are mailed, whichever is later. For properties under $1,000,000, you must first appeal to the County Board of Taxation. If you disagree with the County Board's decision, you can then appeal to Tax Court, typically by April 1 of the following year as specified in the Board's judgment.

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 →

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← All New Jersey property tax appeal info

Sources: https://www.mercercounty.org/government/board-of-taxation | https://www.mercercounty.org/government/board-of-taxation/appeal-brochure | http://www.tax-rates.org/new_jersey/mercer_county_property_tax | https://www.ownwell.com/trends/new-jersey/mercer-county | https://www.nj.gov/treasury/taxation/lpt/lpt-seniordeduction.shtml | https://www.nj.gov/treasury/taxation/lpt/lpt-disabledvet.shtml | https://en.wikipedia.org/wiki/Mercer_County,_New_Jersey | https://worldpopulationreview.com/us-counties/new-jersey/mercer-county

Last verified: 2026-03-05