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Updated 2025 Tax Year

Washington County
Property Tax Guide

Everything you need to know about property taxes in Washington County, MO. 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
16.4062 per $100 of assessed value (varies by district - actual rates depend on school, fire, and special taxing districts)
Exemptions
5+ Available
Section 1

How Property Tax Works

Washington County, Missouri operates under a property tax system that funds essential local services including schools, county government operations, fire protection, and other municipal services. Property owners pay taxes based on their property's assessed value multiplied by the applicable tax rate, which varies significantly by location within the county due to overlapping special taxing districts.

For the 2025 tax year, the certified tax rate for Washington County is 16.4062 per $100 of assessed value, though this represents just one rate configuration within the county. Your actual tax rate depends on which school district, fire district, ambulance district, and other special taxing jurisdictions your property falls within. Missouri assesses residential property at 19% of true market value, meaning a $300,000 home would have an assessed value of approximately $57,000. Property taxes in Washington County fund critical services, with school districts typically representing the largest portion of your total tax bill.

Section 2

What Makes Up Your Tax Bill

ComponentRate (per $100 assessed)Description
County GeneralVariesBasic county operations and services
School DistrictVaries by districtLocal school district operations and debt service
Fire ProtectionVaries by districtLocal fire department funding
Ambulance DistrictVaries by districtEmergency medical services
Library DistrictVaries by districtPublic library system funding
Road DistrictVaries by districtLocal road maintenance and improvement
Sample Total16.4062One certified rate configuration for FY 2025

Note: The 16.4062 rate shown represents one specific tax rate configuration within Washington County for the 2025 levy year. Your actual rate will depend on your property's location and which combination of school districts, fire districts, ambulance districts, and other special taxing jurisdictions serve your area. Contact the Washington County Assessor's office to determine your specific tax rate based on your property's exact location.

Section 3

When Are Property Taxes Due?

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

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 tax assessments in Washington County occur when there are changes in property ownership or completion of new construction during the tax year. These "supplemental events" trigger a reassessment that results in additional tax bills beyond your regular annual property tax bill.

When a supplemental event occurs, the County Assessor calculates the difference between the new assessed value and the previous value that was set on January 1st of the tax year. This difference becomes the supplemental assessment value, which is then prorated to cover the period from the first day of the month following the supplemental event through the end of the fiscal year. For example, if you purchase a home in June that was previously assessed at $50,000 but now appraises at $70,000, you would receive a supplemental bill based on the $20,000 increase in assessed value, prorated for July through December. The supplemental bill is separate from and in addition to the regular annual tax bill, ensuring that property taxes reflect current ownership and improvements throughout the tax year.

Example Calculation

Example 1: $300,000 Home

  • Market Value: $300,000
  • Assessed Value (19%): $57,000
  • Less: Homestead Credit (if applicable): -$1,000
  • Net Taxable Value: $56,000
  • Annual Tax ($56,000 × 16.4062 ÷ 100): $918.75
  • Monthly Payment: $76.56

Example 2: $600,000 Home

  • Market Value: $600,000
  • Assessed Value (19%): $114,000
  • Less: Homestead Credit (if applicable): -$1,000
  • Net Taxable Value: $113,000
  • Annual Tax ($113,000 × 16.4062 ÷ 100): $1,853.90
  • Monthly Payment: $154.49

Example 3: $1,000,000 Home

  • Market Value: $1,000,000
  • Assessed Value (19%): $190,000
  • Less: Homestead Credit (if applicable): -$1,000
  • Net Taxable Value: $189,000
  • Annual Tax ($189,000 × 16.4062 ÷ 100): $3,100.77
  • Monthly Payment: $258.40

Note: These calculations use the sample rate of 16.4062 and assume eligibility for homestead tax credits. Tax credits require separate applications and are not automatically applied. Your actual rate may differ based on your property's specific taxing districts.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Washington County require property tax escrow accounts, where you pay 1/12 of your estimated annual property taxes with each monthly mortgage payment. Your lender holds these funds in escrow and pays your property taxes directly to the county when due. Washington County property taxes are typically paid in two installments: the first installment is due by April 1st, and the second installment is due by October 1st of each year.

Your lender will conduct an annual escrow analysis to ensure adequate funds are collected, adjusting your monthly payment if necessary based on actual tax bills and assessment changes. If your property taxes increase due to reassessment or rate changes, your monthly escrow payment will be adjusted accordingly. You can verify that your lender has made timely payments by checking with the Washington County Collector's office or through their online payment system. Property owners remain ultimately responsible for ensuring taxes are paid even when using escrow, so it's important to monitor that payments are made correctly and on time.

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 Washington County property taxes due for the current fiscal year? A: For the 2025-2026 fiscal year, the first installment is due by April 1, 2026, and the second installment is due by October 1, 2026. Payments can be made online or in person at the collector's office.

Q: What property tax credits are available in Washington County and do I need to apply? A: Missouri offers several tax credits including the Homestead Preservation Credit for seniors, disabled veterans credits, and agricultural use credits. Most credits require separate applications and are NOT automatically applied to your bill. Contact the Washington County Assessor's office for specific application requirements and deadlines.

Q: How does the Homestead Preservation Credit work? A: The Homestead Preservation Credit limits annual assessment increases rather than reducing your home's market value. Eligible seniors and disabled homeowners must file an application to cap assessment growth. This credit requires annual or periodic reapplication - it is not automatic.

Q: How often are properties reassessed in Washington County? A: Missouri law requires properties to be reassessed periodically. Contact the Washington County Assessor's office for the current reassessment schedule and to learn about the appeals process if you disagree with your assessment.

Q: What happens if I pay my property taxes late? A: Late payments incur penalties and interest charges. Delinquent taxes may eventually result in tax sale proceedings. Contact the Washington County Collector's office immediately if you cannot make timely payments to discuss options.

Q: Can I pay my property taxes online? A: Yes, Washington County offers online payment options. Visit the Washington County Collector's website for secure online payment processing and to view your current tax bill status.

Q: Why did my tax bill increase when tax rates didn't change? A: Tax bills can increase due to rising property assessments, new special district taxes, voter-approved bond measures, or loss of previously applied tax credits. Your bill may also include supplemental assessments from property improvements or ownership changes.

Q: How do special taxing districts affect my property tax rate? A: Your total tax rate is the sum of all taxing districts that serve your property, including school districts, fire districts, ambulance districts, and library districts. Properties in different areas of Washington County pay different total rates based on which districts provide services to that location.

Verified Sources

Backed by 10 Official Government Sources

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

01
County
Washington County Public Access > Property Detailwashcotax.co.washington.or.us
02
County
April 8, 2025 Sample Ballots - Washington County Clerkwashcoclerkmo.gov
03
State
2025 Property Tax Rate Report - Missouri State Auditor's Officeauditor.mo.gov
04
Assessed Valuewashmo.gov
05
County
Washington County Courthousewashingtoncountymo.us
06
Collectorwashingtoncountymo.us
07
State
State of Washingtondor.wa.gov
08
Tax Doc
Delinquent Taxeswashingtoncountyclerk.ky.gov
09
County
Sur Tax - Washington County Clerkwashcoclerkmo.gov
10
Tax Doc
Supplemental Tax Bill Infosbcountyatc.gov
All sources verified as of 2025 Tax Year

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