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Updated 2025 Tax Year

Washington County
Property Tax Guide

Everything you need to know about property taxes in Washington County, OK. Rates, due dates, exemptions, and how it affects your monthly payment.

10 Official Sources
8 min read
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Quick Facts
Tax Rate
0.01% base county rate plus variable district taxes - total rate varies significantly by location within county
1st Due
Oct 17
Exemptions
5+ Available
Section 1

How Property Tax Works

Washington County, Oklahoma operates on a property tax system that funds essential local services including schools, roads, law enforcement, and county operations. For fiscal year 2025-26, the county's property tax rate is approximately 0.01%, though this represents just one component of your total property tax bill. The complete tax rate varies significantly by location within the county due to special taxing districts such as school districts, municipal services, and local improvement districts.

Approximately 207,000 property tax statements are mailed to Washington County property owners between October 17 and 21 each year, accounting for a total of $1.742 billion in property taxes that fund local government services. Your actual tax rate depends on which special taxing districts serve your property, meaning two homes of equal value in different parts of the county may have different tax bills. Property owners should verify their specific tax rate and applicable districts with the Washington County Assessor's office.

Section 2

What Makes Up Your Tax Bill

ComponentRateDescription
County General0.01%Basic county services (FY 2025-26)
School DistrictVariesLocal school district operations and bonds
MunicipalVariesCity services (if within city limits)
Special DistrictsVariesFire districts, library districts, etc.
Total Effective RateVaries by locationCombination of all applicable districts

Note: The 0.01% county rate applies to fiscal year 2025-26 with no planned increases for 2025. Your total effective tax rate will be higher due to school districts and other special assessments. Contact the Washington County Assessor at (918) 337-2870 for your property's specific rate breakdown.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Washington County, property taxes are due in two installments:

First Installment
Oct 17
Delinquent after Dec 10
Pro tip: If you pay through mortgage escrow, your lender splits these payments across your monthly mortgage. If you pay directly, set calendar reminders to avoid late penalties.
Section 4

Supplemental Tax Bills

Supplemental taxes in Washington County are triggered by changes in property ownership, new construction, or improvements that increase a property's assessed value during the tax year. The county's ad valorem tax is levied each October 1 on the assessed value listed as of January 1 of the same year for all real and personal property.

When supplemental taxes are issued, they are calculated on the difference between the original assessed value and the new assessed value, prorated for the portion of the tax year remaining. For example, if you complete a $50,000 home addition in June, you would receive a supplemental tax bill covering July through the end of the fiscal year based on the increased assessed value from that improvement.

Example Calculation

Example 1: $300,000 Home

  • Market Value: $300,000
  • Assessed Value (11.5% ratio): $34,500
  • Less: Homestead Credit (if applied): -$1,000
  • Net Taxable Value: $33,500
  • Annual Tax (assuming 1.2% total rate): $402
  • Monthly Payment: $34

Example 2: $600,000 Home

  • Market Value: $600,000
  • Assessed Value (11.5% ratio): $69,000
  • Less: Homestead Credit (if applied): -$1,000
  • Net Taxable Value: $68,000
  • Annual Tax (assuming 1.2% total rate): $816
  • Monthly Payment: $68

Example 3: $1,000,000 Home

  • Market Value: $1,000,000
  • Assessed Value (11.5% ratio): $115,000
  • Less: Homestead Credit (if applied): -$1,000
  • Net Taxable Value: $114,000
  • Annual Tax (assuming 1.2% total rate): $1,368
  • Monthly Payment: $114

Note: Homestead and other tax credits require application and are not automatic. Actual rates vary by special district location.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Washington County require property tax escrow accounts, collecting monthly payments along with your mortgage payment. Lenders typically collect 1/12th of your annual property tax bill each month, plus an additional buffer amount to ensure sufficient funds when taxes are due.

Property tax payments are due in two installments: the first half by May 15 and the second half by October 15. Annual statements are mailed by October 25 with payments due by November 15. Your lender will receive a copy of your tax bill and should make payments directly to Washington County Treasurer Scott Henke's office. You can verify that your lender has made payments by checking the county's online payment system or contacting the Treasurer's office at (918) 337-2800.

How HonestCasa Helps
  • Understand whether your escrow is set correctly
  • See how rising taxes will change your monthly payment
  • Plan ahead instead of being surprised by "shortage" letters
Section 6

Frequently Asked Questions

Q: When are property taxes due in Washington County for FY 2025-26? A: First half payments are due May 15, second half due October 15. Annual statements are mailed between October 17-21, with payments due by November 15.

Q: What tax credits are available and do I need to apply? A: Homestead exemptions, senior citizen credits, and disabled veteran exemptions are available but require application. These are NOT automatic and must be filed with the County Assessor by March 15 for the following tax year.

Q: How does the homestead credit work? A: The homestead exemption limits assessment increases and provides some tax reduction, but you must apply by March 15. If filed after March 15, it takes effect the following tax year. Contact the County Assessor for current exemption amounts and applications.

Q: When are properties reassessed? A: Oklahoma conducts annual assessments with values set as of January 1 each year. You'll receive assessment notices in spring with appeal deadlines typically in June.

Q: What are the penalties for late payment? A: Contact the Washington County Treasurer's office at (918) 337-2800 for current penalty rates and payment options.

Q: Can I pay property taxes online? A: Yes, Washington County offers online payment options. Check the county website or contact the Treasurer's office for available payment methods.

Q: Why do tax rates vary within Washington County? A: Your total rate depends on school districts, municipal boundaries, and special districts (fire, library, etc.) that serve your property location.

Q: How do I appeal my property assessment? A: Contact the Washington County Assessor's office at (918) 337-2870 for appeal procedures and deadlines, typically due in June following the assessment notice.

Q: Where can I get help understanding my tax bill? A: The County's Department of Assessment & Taxation staff assist with inquiries about how property tax bills are determined, what services are funded, and appeal options.

Verified Sources

Backed by 10 Official Government Sources

Every fact in this guide is sourced from official county, state, and federal documents.

01
State
2025-26 Property Tax Statementwashingtoncountyor.gov
02
County
Washington County Will Not Raise Taxes for the 16th Year ...washco.utah.gov
03
General Information and Frequently Asked Questionswashingtoncountyor.gov
04
County
Washington County Property Taxesoakdalemn.gov
05
County
Washington County Public Access > Homewashcotax.co.washington.or.us
06
2026-2027 Form 921 Application for Homestead Exemptionoklahoma.gov
07
2026 Form 994 Application for Property Valuation Limitation ...oklahoma.gov
08
January 2025 Vol. 15washcowisco.gov
09
County
Washington County - Oklahoma Digital Prairiedigitalprairie.ok.gov
10
County
News - Washington County, WIwashcowisco.gov
All sources verified as of 2025 Tax Year

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