AppealDesk

Mercer County Property Tax Appeal — Ohio

Rob HartleyRob Hartley·Updated April 3, 2026

Mercer County is located in western Ohio along the Indiana border, with Celina serving as the county seat. With a population of approximately 42,500, the county is home to notable cities including Coldwater, St. Henry, and Fort Recovery. Mercer County's median home value of $129,600 is significantly below the national median, yet its effective property tax rate of 1.53% is notably higher than the national median of 1.02%. The county's median annual property tax bill of $1,932 remains below the national median of $2,400, making property tax appeals particularly valuable for homeowners seeking to challenge potentially inflated assessments.

Notable cities: Celina, Coldwater, St. Henry, Fort Recovery

Median Home

$129,600

Tax Rate

1.53%

Annual Tax

$1,932

Population

42,528

2026 Appeal Deadline: March 31, 2026

For tax year 2025 assessments, property owners must file a complaint with the Mercer County Board of Revision between January 1, 2026 and March 31, 2026. The complaint must be received by the County Auditor's office or postmarked by March 31, 2026. Late filings are not accepted, and there are no extensions to this deadline set by Ohio Revised Code 5715.19.

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

How Mercer County Assesses Property

35%of market value

Assessed by: Mercer County Auditor's Office

Assessment cycle: triennial

Notices typically mailed: Spring (mid-April)

In Mercer County, property taxes are calculated based on the assessed value, which is 35% of the property's market value as determined by the County Auditor. The county undergoes a triennial update every three years to reflect recent changes in the real estate marketplace. For example, if your home's market value is $129,600, at Ohio's 35% assessment ratio your assessed value would be $45,360, resulting in approximately $1,982 in annual taxes at the county's effective rate of 1.53%.

The Appeal Process

Appeals are heard by the Board of Revision. The Mercer County Board of Revision consists of three members: the County Auditor, County Treasurer, and a County Commissioner. Hearings are quasi-judicial proceedings where you will present evidence supporting your requested property value, and the burden of proof falls on the complainant to justify a change in value.

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Step 1: Verify your current assessed value by visiting the Mercer County Auditor's property search tool at https://auditor.mercercountyohio.gov or by contacting the Auditor's office at(419) 586-6402.

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Step 2: Gather supporting evidence including recent comparable sales of similar properties in your area, a professional appraisal dated within the last three years, photographs showing property condition issues, repair estimates, or insurance documentation.

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Step 3: Complete DTE Form 1 (Complaint Against the Valuation of Real Property) in its entirety, ensuring all required fields are filled out and the form is notarized. Download the form from the County Auditor's website or request it by phone.

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Step 4: Submit your complaint along with all supporting documentation to the Mercer County Auditor's office by mail or in person. The complaint must be received or postmarked by March 31, 2026. Include your contact information including email address if available.

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Step 5: Attend your scheduled Board of Revision hearing, which will be scheduled within 30-90 days of filing. Present your evidence to the three-member panel consisting of the County Auditor, County Treasurer, and a County Commissioner representative. Hearings typically last 15-30 minutes.

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Step 6: Receive the Board's written decision by mail, typically within 2-3 weeks after your hearing. If you disagree with the decision, you have 30 days from the date of mailing to appeal to the Ohio Board of Tax Appeals or Court of Common Pleas.

Required form: DTE Form 1 (Complaint Against the Valuation of Real Property)

Filing Methods

mail:Mercer County Auditor, 101 North Main Street, Room 105, Celina, OH 45822. Must be notarized and postmarked by March 31, 2026.
in-person:101 North Main Street, Room 105, Celina, OH 45822. Office hours: Monday 8:30 AM - 5:00 PM, Tuesday-Friday 8:30 AM - 4:00 PM.
phone:Call(419) 586-6402 to request appeal forms and instructions.

Evidence to Bring

Recent comparable sales of similar properties (within last 3 years)Professional appraisal report (certified, not more than 3 years old)Photographs documenting property condition or damageRepair estimates or contractor invoicesInsurance information showing insured valueRecent listing agreements if property was listed for sale

Mercer County Assessor Contact

Mercer County Auditor's Office

Phone: ((419) 586-6402

Address: 101 North Main Street, Room 105, Celina, OH 45822

Website: https://auditorhttps://.mercercountyohio.gov/

Hours: Monday: 8:30 AM - 5:00 PM, Tuesday-Friday: 8:30 AM - 4:00 PM, Closed Federal Holidays

Tax Exemptions in Mercer County

Homestead Exemption (Seniors and Disabled)

$29,000 of market value exempted (for tax year 2026)

Reduces property taxes by exempting the first $29,000 of the home's market value from taxation for qualified senior citizens and disabled persons.

Eligibility: Must be 65 years or older by December 31 of the application year, OR permanently and totally disabled as of January 1, AND own and occupy the property as primary residence, AND have Ohio Modified Adjusted Gross Income of $41,000 or less for 2025.Deadline: December 31 annually

Enhanced Homestead Exemption (Disabled Veterans)

$58,000 of market value exempted (for tax year 2026)

Enhanced exemption for qualifying disabled veterans and surviving spouses of public service officers killed in the line of duty.

Eligibility: Must be a veteran with 100% service-connected disability rating OR surviving spouse of a public service officer killed in the line of duty. Must own and occupy the property as primary residence. No income requirement.Deadline: December 31 annually

Owner Occupancy Credit

2.5% reduction in taxes

Provides a 2.5% reduction in assessed value for owner-occupied residential properties.

Eligibility: Must own and occupy the property as primary residence as of January 1 of the tax year.Deadline: Contact County Auditor for application details

Official Resources

Mercer County Auditor - Official Website →

Access property records, assessment information, tax estimates, and downloadable appeal forms from the official Mercer County Auditor's website.

Mercer County Property Search Tool →

Search for your property's current assessed value, tax history, and property record card to verify assessment details before filing an appeal.

Ohio Department of Taxation - Property Tax Resources →

Download official DTE forms, learn about homestead exemptions, and access statewide property tax guidance from the Ohio Department of Taxation.

Ohio Board of Tax Appeals →

File second-level appeals, access appeal guides, and learn about the state-level property tax appeals process if dissatisfied with local Board of Revision decisions.

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 appeal your 2025 property tax assessment in Mercer County is March 31, 2026. Your complaint must be filed with the Mercer County Board of Revision between January 1, 2026 and March 31, 2026. The complaint must either be received by the County Auditor's office or postmarked by the U.S. Postal Service on or before March 31, 2026. Private meter postmarks are not valid for establishing the filing date. Late filings are not accepted under Ohio law, and there are no extensions or exceptions to this deadline, so it's critical to file early to avoid missing this window.
How do I file a property tax appeal in Mercer County?
To file a property tax appeal in Mercer County, you must complete DTE Form 1 (Complaint Against the Valuation of Real Property), which can be downloaded from https://auditor.mercercountyohio.gov or requested by calling(419) 586-6402. The form must be filled out completely, notarized, and submitted along with supporting evidence such as comparable sales, appraisals, or photos documenting property issues. You can file by mailing the form to Mercer County Auditor, 101 North Main Street, Room 105, Celina, OH 45822, or by delivering it in person during office hours (Monday 8:30 AM-5:00 PM, Tuesday-Friday 8:30 AM-4:00 PM). The complaint must be received or postmarked by March 31, 2026.
What evidence do I need to win my property tax appeal in Mercer County?
To successfully appeal your property taxes in Mercer County, you need to provide strong evidence supporting your claim that your property is overvalued. The most effective evidence includes a certified appraisal not more than three years old, recent comparable sales of similar properties in your neighborhood, photographs showing property condition issues or damage, repair estimates from licensed contractors, and insurance documentation showing insured value. The Board of Revision will not consider vague complaints or tax rate arguments - you must provide concrete documentation that proves your property's market value is lower than the Auditor's assessment as of January 1 of the tax year. Submit all evidence with your initial complaint or at least 5-10 days before your scheduled hearing.
How much can I save by appealing my property taxes in Mercer County?
The amount you can save by appealing your property taxes in Mercer County depends on how much your property's assessed value is reduced. With Mercer County's effective tax rate of 1.53%, every $10,000 reduction in your property's market value translates to approximately $54 in annual tax savings (calculated as $10,000 × 35% assessment ratio × 1.53% tax rate). For example, if you successfully reduce your home's assessed value from $150,000 to $130,000, you would save approximately $107 annually. The Homestead Exemption, which exempts $29,000 in market value for qualifying seniors and disabled persons, typically provides $400-$450 in annual savings for eligible homeowners.
What happens at a Board of Revision hearing in Mercer County?
At a Mercer County Board of Revision hearing, you will appear before a three-member panel consisting of representatives from the County Auditor, County Treasurer, and County Commissioners' offices. The hearing is a quasi-judicial proceeding that typically lasts 15-30 minutes, during which you will present evidence supporting your opinion of your property's value. You'll need to explain why you believe your property is overvalued, present comparable sales data, appraisals, or other documentation, and answer questions from the Board members. The Auditor's office may also present their evidence supporting the current valuation. After reviewing all evidence and testimony, the Board will issue a written decision within 2-3 weeks, which will either maintain, reduce, or potentially increase your property's assessed value.
What is the homestead exemption worth in Mercer County?
The Homestead Exemption in Mercer County exempts the first $29,000 of your home's market value from property taxation for qualifying seniors (age 65+) and disabled homeowners with household income of $41,000 or less. With Mercer County's effective tax rate of 1.53%, this exemption typically saves eligible homeowners approximately $155 annually (calculated as $29,000 × 35% assessment ratio × 1.53%). Veterans with 100% service-connected disabilities qualify for an enhanced exemption of $58,000 in market value with no income requirement, providing approximately $310 in annual tax savings. To apply, contact the Mercer County Auditor's office at(419) 586-6402 or download form DTE 105A from their website. Applications must be filed by December 31 annually.
Can I appeal my Mercer County property taxes every year?
Under Ohio law, property owners in Mercer County are generally limited to filing one Board of Revision complaint per parcel during each triennial assessment period (every three years) unless specific exceptions apply. You can file more frequently if you can demonstrate one of the following: your property was sold, you made substantial improvements or suffered damage to the property, or there was a change in zoning or use. Mercer County conducts a triennial update every three years, with the most recent occurring in 2026, which reviews property sales from the preceding three years. Even if you cannot file a formal appeal, you can always contact the Auditor's office to discuss concerns about your assessment or request an informal review of your property value.
What if I disagree with the Board of Revision decision in Mercer County?
If you disagree with the Mercer County Board of Revision's decision, you have the right to appeal to a higher authority within 30 days from the date the decision notice is mailed to you. You can file an appeal with either the Ohio Board of Tax Appeals (BTA) using DTE Form 4, available at https://bta.ohio.gov, or with the Mercer County Court of Common Pleas. You must file a copy of your notice of appeal with both the Board of Revision and the appellate body within the 30-day timeframe, or your appeal rights will be lost. The BTA can be reached at(614) 466-6700 for guidance on the appeals process. If you miss this deadline, you'll have to wait until the next appeal filing period to challenge your assessment again.

For state-wide appeal information including Ohio's assessment ratio and deadlines, see our Ohio 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 Ohio property tax appeal info

Sources: https://auditorhttps://.mercercountyohio.gov/ | https://www.ownwell.com/trends/ohio/mercer-county | https://www.mercercountyohio.org/elected-officials/auditor/ | https://www.mercercountyohio.org/elected-officials/treasurer/faq/ | https://en.wikipedia.org/wiki/Mercer_County,_Ohio | https://tax.ohio.gov/real_property | https://bta.ohio.gov/

Last verified: 2026-04-03