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Updated 2025 Tax Year

Thurston County
Property Tax Guide

Everything you need to know about property taxes in Thurston County, WA. 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
$9.828 per $1,000 assessed value (2025 countywide average), varies by taxing districts
1st Due
Apr 30
2nd Due
Oct 31
Exemptions
5+ Available
Section 1

How Property Tax Works

Thurston County, Washington operates under a property tax system that serves as the primary funding mechanism for local government services, including schools, fire protection, emergency medical services, and county operations. The county's property tax system is administered by the Thurston County Assessor's Office, which determines property values, and the Treasurer's Office, which collects taxes.

For the 2025 tax year, the countywide average levy rate is $9.828 per thousand dollars of assessed value, representing an increase from the 2024 rate of $9.688 per thousand. However, actual tax rates vary significantly by location within Thurston County due to different combinations of special taxing districts, including school districts, fire districts, library districts, and other local improvement districts. Property owners should expect their specific rate to differ from the county average based on the particular taxing districts that serve their property location.

Property taxes in Thurston County are assessed annually based on 100% of fair market value as of January 1st each year. Unlike some states, Washington does not impose a statewide assessment cap, though individual levy increases are subject to statutory limitations. The tax system funds essential services and represents a significant revenue source for maintaining community infrastructure and public safety services throughout the county.

Section 2

What Makes Up Your Tax Bill

ComponentRate RangeDescription
County General~$1.80-2.50 per $1,000Basic county services, roads, law enforcement
School Districts~$4.00-6.00 per $1,000K-12 education funding (varies by district)
Fire/EMS Districts~$1.00-2.00 per $1,000Fire protection and emergency medical services
Port Districts~$0.20-0.60 per $1,000Economic development and infrastructure
Library Districts~$0.30-0.50 per $1,000Public library services
Special AssessmentsVariesLocal improvement districts, bonds

Levy Year: 2025 (taxes due in 2025) County Average Total: $9.828 per $1,000 of assessed value

Note: Individual property tax rates vary significantly based on location within Thurston County. Properties may be subject to additional special district levies including hospital districts, cemetery districts, or local improvement assessments. Contact the Thurston County Assessor at (360) 786-5408 for your specific rate breakdown.

Section 3

When Are Property Taxes Due?

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

First Installment
Apr 30
Delinquent after Dec 10
Second Installment
Oct 31
Delinquent after Apr 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 tax assessments in Thurston County occur when there are significant changes to a property during the tax year that affect its assessed value. The most common triggers include new construction completion, major renovations or improvements, and changes in property ownership that reveal previously unassessed improvements.

When new construction is completed or substantial improvements are finished after the January 1st assessment date, the county assessor calculates a prorated supplemental assessment based on the increased value and the remaining months in the tax year. For example, if a $100,000 addition is completed on July 1st, the supplemental tax would apply to that additional value for the remaining 6 months of the tax year.

Supplemental tax bills are calculated using the same tax rate that applies to the property's base assessment and are typically issued within 30-60 days after the assessor determines the value change. These taxes become due immediately upon issuance and follow the same penalty structure as regular property taxes if not paid timely. Property owners should budget for potential supplemental assessments when planning major improvements or completing new construction projects.

Example Calculation

Example 1: $300,000 Home

  • Market/Assessed Value: $300,000
  • Senior Citizen Tax Deferral (if applicable): Not a reduction, defers 2nd half payment
  • Net Taxable Value: $300,000
  • Tax Rate: $9.828 per $1,000
  • Annual Tax: $2,948.40
  • Monthly Escrow: $245.70

Example 2: $600,000 Home

  • Market/Assessed Value: $600,000
  • Disabled Veteran Exemption (if qualified): Up to $40,000 value exemption*
  • Net Taxable Value: $560,000 (with exemption)
  • Tax Rate: $9.828 per $1,000
  • Annual Tax: $5,503.68
  • Monthly Escrow: $458.64

Example 3: $1,000,000 Home

  • Market/Assessed Value: $1,000,000
  • No Credits Applied: $1,000,000
  • Net Taxable Value: $1,000,000
  • Tax Rate: $9.828 per $1,000
  • Annual Tax: $9,828.00
  • Monthly Escrow: $819.00

All exemptions and deferrals require annual application and income/qualification verification. Contact the Thurston County Assessor at (360) 786-5408 for application requirements and deadlines.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Thurston County require borrowers to maintain an escrow account for property tax payments, particularly for loans with less than 20% down payment. Lenders collect monthly escrow payments as part of your mortgage payment and remit property taxes directly to the Thurston County Treasurer on your behalf. The escrow amount is calculated by dividing your annual property tax bill by 12, often with an additional cushion to account for potential tax increases.

Property taxes in Thurston County are payable in two installments: the first half is due April 30th and the second half is due October 31st each year. Lenders typically pay both installments on time to avoid penalties. Your mortgage servicer will provide an annual escrow analysis, usually in connection with your mortgage statement, showing the previous year's activity and any adjustments needed for the coming year.

If your property taxes increase due to reassessment or rate changes, your lender may require higher monthly escrow payments or may advance the shortage and recover it over the following year. Property owners should review their annual escrow statements carefully and contact their lender immediately if they notice discrepancies. You can verify that your taxes were paid correctly by checking the Thurston County Treasurer's website at co.thurston.wa.us/treasurer or calling (360) 786-5550.

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Section 6

Frequently Asked Questions

Q: When are 2025 property taxes due in Thurston County? A: First half taxes are due April 30, 2025, and second half taxes are due October 31, 2025. Payments postmarked by the due dates are considered timely.

Q: What tax credits are available and do I need to apply? A: The Senior Citizens and Disabled Persons Property Tax Deferral Program helps eligible individuals defer the second half payment. Disabled veterans may qualify for property tax exemptions. All programs require annual application with income verification. Applications are typically due by December 31st for the following tax year.

Q: Is there a Homestead credit that limits assessment increases? A: Washington State does not have a traditional homestead credit that caps assessment growth. However, levy increases are limited by state law to 1% annually plus new construction, which helps moderate tax increases over time.

Q: How often are properties reassessed? A: Properties are reassessed annually as of January 1st. The Thurston County Assessor reviews market sales data and may physically inspect properties on a rotating cycle to ensure accurate valuations.

Q: What happens if I pay my property taxes late? A: Late payments incur penalties: 3% if paid in June (first half) or December (second half), 8% if paid by October 31st (first half) or by the following April 30th (second half), and 12% thereafter plus potential foreclosure proceedings.

Q: Can I pay property taxes online? A: Yes, Thurston County accepts online payments through their website at co.thurston.wa.us/treasurer. Credit cards, e-checks, and ACH transfers are accepted, though convenience fees may apply.

Q: How do special district taxes affect my bill? A: Special districts like fire, school, library, and hospital districts add their levies to your base county tax rate. Your specific rate depends on which districts serve your property location. The same property tax bill covers all applicable districts.

Q: How do I appeal my property assessment? A: Assessment appeals must be filed by July 1st with the Thurston County Board of Equalization. You can appeal online, by phone at (360) 786-5408, or by written petition. Provide comparable sales data or evidence that your assessed value exceeds fair market value.

Verified Sources

Backed by 10 Official Government Sources

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

01
Tax Doc
2025 PROPERTY TAX FACT SHEET & LEVY DATAthurstoncountywa.gov
02
Tax Doc
PROPERTY TAX STATISTICS 2025dor.wa.gov
03
Tax Doc
Tax Ratesthurstoncountywa.gov
04
Tax Doc
Second Half of 2025 Property Taxes Due October 31thurstoncountywa.gov
05
Tax Doc
2023 1st Half Property Taxes Due April 30thurstoncountywa.gov
06
Tax Doc
2024 1st Half Property Taxes Due April 30thurstoncountywa.gov
07
Tax Doc
Property Tax Relief Programsthurstoncountywa.gov
08
Tax Doc
Multifamily Tax Exemptionolympiawa.gov
09
Homeowner Grant Program for Septic System Maintenancethurstoncountywa.gov
10
County
Thurston County Comprehensive Planapps.ecology.wa.gov
All sources verified as of 2025 Tax Year

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