Union County Property Tax Appeal, Ohio

Travis Bunn·Updated July 25, 2026

Union County is located in central Ohio, northwest of Columbus, with Marysville serving as the county seat. The county has experienced rapid residential growth, with its population increasing 20% over the past decade to approximately 73,700 residents as of 2025. With a median home value of $306,600 and an effective property tax rate of 1.25%, Union County homeowners pay a median annual tax bill of $3,847, which is above the national median of $2,400 but slightly below Ohio's state average rate of 1.36%. The county's strong industrial base, including Honda manufacturing, and proximity to Columbus have driven both population and property value growth, making property tax appeals an important consideration for homeowners facing rising assessments.

Notable cities: Marysville, Dublin, Richwood, Plain City, Milford Center

Median Home

$306,600

Tax Rate

1.25%

Annual Tax

$3,847

Population

73,700

On the typical Union County home, valued near $306,600 at the county’s effective tax rate of 1.25%, an over-assessment of even 10% means you are overpaying year after year until you appeal it. Here is how to find out if yours qualifies.

2026 Appeal Deadline: March 31, 2026

This year's appeal window has passed in most of Ohio. Order now and we re-run your numbers free when the window reopens, so your evidence is ready the day your next notice lands.

According to Ohio Revised Code Section 323.13 and Union County guidelines, complaints for the 2025 tax year (payable in 2026) must be filed between January 1, 2026 and March 31, 2026. The March 31 deadline is firm with no extensions. Mailed complaints must be received by March 31 unless they bear a USPS postmark of March 31 or earlier.

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Ohio residential street of family homes. Union County appeal guide.

How Union County Assesses Property

35%of market value

Assessed by: Union County Auditor's Office

Assessment cycle: triennial

Notices typically mailed: Spring (typically by mid-March)

In Union County, as throughout Ohio, properties are assessed at 35% of their market value. This means your assessed value is the figure used to calculate your property taxes, not the full market value. For example, if your home's market value is $306,600 (Union County's median), your assessed value would be $107,310 (35% of $306,600). At Union County's effective tax rate of 1.25%, this results in approximately $3,847 in annual property taxes. Union County conducts a full sexennial reappraisal every six years (last conducted in 2019, next in 2025), with a triennial update at the three-year midpoint (completed in 2022) to reflect market changes.

The Appeal Process

Appeals are heard by the Board of Revision. The Union County Board of Revision consists of the County Auditor, County Treasurer, and a County Commissioner. After filing, your complaint will be reviewed by a staff appraiser, and you may be scheduled for a hearing where you'll have 5-15 minutes to present your evidence. The Board can raise, lower, or maintain your property's value based on the evidence presented.

Review your property assessment notice (mailed in spring) and compare your property's market value to recent sales of similar properties in Union County using the county's Beacon property search tool at https://beacon.schneidercorp.com/Application.aspx?App=UnionCountyOH&PageType=Search

Gather evidence to support your appeal, including recent comparable sales (within the past 12-24 months), photographs of property condition issues, recent appraisals, repair estimates, or documentation showing errors in the property record (incorrect square footage, bedrooms, etc.)

Complete DTE Form 1 (Complaint Against the Valuation of Real Property) available from the Union County Auditor's website or Ohio Department of Taxation. The form must be notarized and include your proposed market value with supporting documentation.

File your notarized complaint with all supporting evidence by March 31, 2026 via email (auditor@unioncountyohio.gov), mail, fax (937-645-3057), or in person at the Auditor's Office. Include copies of comparable sales, photographs, and any other evidence supporting your proposed value.

Attend the Board of Revision hearing if scheduled. The Union County Board of Revision (consisting of the County Auditor, County Treasurer, and a County Commissioner) will review your evidence and may schedule an informal hearing. Present your case clearly and concisely, focusing on market value evidence.

Receive the Board of Revision's decision. The BOR can increase, decrease, or maintain your property's value. The decision applies to the current tax year through the next county-wide update or reappraisal.

If you disagree with the Board of Revision decision, appeal to the Ohio Board of Tax Appeals (using DTE Form 4) within 30 days of the BOR decision, or to the Court of Common Pleas. Further appeals can be made to the Ohio Supreme Court if necessary.

Required form: DTE Form 1 (Complaint Against the Valuation of Real Property) or DTE Form 2 (for non-market value issues)

Filing Methods

email:Email notarized application and supporting documents to auditor@unioncountyohio.gov

mail:Union County Auditor's Office, ATTN: Board of Revision, 233 W. 6th Street, Marysville, OH 43040

in-person:233 W. 6th Street, 2nd Floor, Marysville, OH 43040 (Monday-Friday, 8:30 AM - 4:00 PM)

fax:Fax notarized application and documents to 937-645-3057

Evidence to Bring

Comparable sales (recent valid arm's-length sales within 24 months of January 1 tax lien date)Property condition documentation (photos of defects, damage, needed repairs)Recent professional appraisalDocumentation of property record errors (incorrect square footage, bedrooms, etc.)Repair estimates for major defectsRecent purchase closing statements if you recently bought the property

Union County Assessor Contact

Union County Auditor's Office

Phone: 937-645-3003

Address: 233 West 6th Street, 2nd Floor, Marysville, OH 43040

Website: https://www.unioncountyohio.gov/auditor

Online Portal: https://beacon.schneidercorp.com/Application.aspx?App=UnionCountyOH&PageType=Search

Hours: Monday - Friday, 8:30 AM - 4:00 PM

Tax Exemptions in Union County

Homestead Exemption (Senior/Disabled)

$29,000 reduction in market value (approximately $395-450 annual savings in Union County)

Reduces taxable value for eligible senior citizens (65+) and permanently disabled homeowners

Eligibility: Must be 65+ or permanently disabled, own and occupy the home as primary residence, and have Ohio Adjusted Gross Income of $41,000 or less for 2026 tax yearDeadline: First Monday in June (annually)

Disabled Veteran Homestead Exemption

$58,000 reduction in market value (approximately $790-870 annual savings in Union County)

Enhanced exemption for 100% service-connected disabled veterans

Eligibility: Must be 100% service-connected disabled veteran certified by VA, own and occupy home as primary residence. No income limit required.Deadline: First Monday in June

Owner-Occupancy Credit (2.5% Rollback)

2.5% reduction on property tax bill

Automatic tax credit for owner-occupied residential properties

Eligibility: Must own and occupy the property as primary residence. Requires one-time application.Deadline: Ongoing (one-time application)

10% Residential Rollback

10% reduction on tax bill for levies passed before November 2013

Automatic tax credit for all non-commercial/industrial properties

Eligibility: Applies automatically to all residential and agricultural properties for qualifying leviesDeadline: Automatic (no application required)

Union County Appeal Packet · $49

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Frequently Asked Questions

What is the deadline to appeal my property taxes in Union County for 2026?

The deadline to file a property tax appeal in Union County for the 2025 tax year (payable in 2026) is March 31, 2026. According to Ohio Revised Code Section 323.13, complaints must be filed between January 1 and March 31 of the year following the tax year being appealed. This deadline is absolute with no extensions or exceptions. If you mail your appeal, it must be received by March 31 or bear a USPS postmark of March 31 or earlier. Missing this deadline means you must wait until the following year to appeal, potentially paying higher taxes for another full year.

How do I file a property tax appeal in Union County?

To file a property tax appeal in Union County, you must complete DTE Form 1 (Complaint Against the Valuation of Real Property), have it notarized, and submit it with supporting evidence by March 31. You can file by emailing the notarized form to auditor@unioncountyohio.gov, mailing it to Union County Auditor's Office, ATTN: Board of Revision, 233 W. 6th Street, Marysville, OH 43040, faxing to 937-645-3057, or filing in person at the Auditor's Office during business hours (Monday-Friday, 8:30 AM - 4:00 PM). Include all supporting documentation such as comparable sales, photographs, and appraisals with your initial filing for the strongest case.

What is the homestead exemption worth in Union County?

The homestead exemption in Union County provides a $29,000 reduction in market value for eligible seniors (65+) and permanently disabled homeowners, which translates to approximately $395-450 in annual tax savings based on the county's 1.25% effective tax rate. To qualify, you must own and occupy your home as your primary residence and have an Ohio Adjusted Gross Income of $41,000 or less for tax year 2026. Disabled veterans with 100% service-connected disability receive an enhanced exemption of $58,000 in market value reduction (approximately $790-870 annual savings) with no income limit. Applications must be filed by the first Monday in June with the Union County Auditor's Office.

What evidence do I need for a successful Union County property tax appeal?

For a successful property tax appeal in Union County, you need compelling evidence that your property's market value is lower than the county's assessment. The strongest evidence includes recent comparable sales of similar properties (within the past 12-24 months of the January 1 tax lien date) showing lower values, a recent professional appraisal, and photographs documenting property condition issues such as foundation cracks, water damage, or needed repairs. You should also verify your property record for errors in square footage, bedrooms, bathrooms, or other features that could inflate your value. Ohio law places the burden of proof on you to demonstrate your property's market value is incorrect, so thorough documentation submitted with your DTE Form 1 is essential.

What happens at a Union County Board of Revision hearing?

At a Union County Board of Revision hearing, you will present your case to a three-member board consisting of the County Auditor, County Treasurer, and a County Commissioner. You typically have 5-15 minutes to present your evidence supporting your proposed property value, including comparable sales, appraisals, and documentation of property issues. The board may ask questions about your property and evidence. After reviewing all information, the Board can increase, decrease, or maintain your property's assessed value. Their decision applies to the current tax year and remains in effect through the next county-wide update or reappraisal. If you disagree with the decision, you have 30 days to appeal to the Ohio Board of Tax Appeals.

Can my property value be increased if I file an appeal in Union County?

Yes, your property value can potentially be increased if you file an appeal in Union County, though not directly by your complaint. When you file a DTE Form 1 seeking a lower valuation, Ohio law allows the school district where your property is located to file a counter-complaint within 30 days arguing that your value should actually be higher. If the change in market value you're seeking exceeds $50,000 (or $17,500 in assessed value), the Board of Revision must notify the school district Board of Education. While your complaint itself can only result in a lower or unchanged value, the school district's counter-complaint can potentially increase your assessment above the original value. This makes it important to have strong evidence before filing.

How does Union County's property tax rate compare to other Ohio counties?

Union County's effective property tax rate of 1.25% is moderately high compared to both state and national averages. It is 0.11% lower than Ohio's state average effective rate of 1.36%, but significantly higher than the national average of 0.91%. With a median home value of $306,600, Union County homeowners pay a median annual tax bill of $3,847, which is above the national median property tax bill of $2,400. The county collects approximately 1.4% of a property's assessed fair market value as property tax according to some sources. Union County ranks among the top third of Ohio's 88 counties for property tax burden, partly due to rapid growth and strong property values driven by Honda manufacturing and proximity to Columbus.

When will Union County conduct its next reappraisal and how does this affect my appeal?

Union County completed a triennial update in 2022 (three years after the 2019 sexennial reappraisal) and is scheduled for its next full sexennial reappraisal in 2025, with the following triennial update in 2028. Ohio law requires county auditors to conduct a full reappraisal of all real property every six years and an update at the three-year midpoint. During reappraisal and update years, property values can change significantly based on market conditions, making those years particularly important for filing appeals if you believe your new assessment is too high. You can appeal any year by March 31, but many homeowners find appeals most necessary following reappraisals when values jump substantially due to market appreciation.

Official Resources

Union County Auditor Website →

Official Union County Auditor's Office website with forms, property search tools, tax information, and Board of Revision resources.

Union County Property Search (Beacon) →

Search Union County property records, view assessments, tax history, GIS maps, and file Board of Revision complaints online.

Ohio Department of Taxation - Real Property Forms →

Download DTE Form 1, DTE Form 2, and other official Ohio property tax appeal forms and instructions.

Union County Board of Revision Information →

Detailed information about the Union County Board of Revision process, filing procedures, deadlines, and what to expect at hearings.

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 →

More Ohio Counties

Adams County (West Union)Allen County (Lima)Ashland County (Ashland)Ashtabula County (Jefferson)Athens County (Athens)Auglaize County (Wapakoneta)

← All Ohio property tax appeal info

Sources: https://www.unioncountyohio.gov/auditor | https://www.unioncountyohio.gov/auditor-faq | https://propertytaxrates.org/counties/ohio/union-county/ | https://www.appealdesk.com/blog/how-to-appeal-property-taxes-in-ohio | https://www.unioncountyohio.gov/homestead-exemption-property-tax-rollbacks

Last verified: 2026-07-25