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Updated 2025 Tax Year

Columbia County
Property Tax Guide

Everything you need to know about property taxes in Columbia 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
0.2061% base county levy, varies significantly by location due to special taxing districts
1st Due
Apr 30
2nd Due
Oct 31
Exemptions
5+ Available
Section 1

How Property Tax Works

Columbia County, Washington operates under a property tax system that funds essential local services including schools, parks and recreation, emergency services, and general county operations. Property taxes are calculated based on assessed value and applied tax rates, with the effective rate for 2025 being approximately 0.2061% for the base county levy. However, actual tax rates vary significantly by location within Columbia County due to special taxing districts such as school districts, park and recreation districts, and bond assessments.

The county uses a split payment system where property owners can pay half their annual tax bill by April 30th, with the remainder due by October 31st if they choose the installment option. Property tax revenues are a critical funding source for local government operations, and the county maintains a lien system to ensure collection of delinquent taxes.

Section 2

What Makes Up Your Tax Bill

Based on the 2025 levy year, Columbia County property tax rates include the following components:

ComponentRateDescription
Base County Levy0.2061374152%General county operations and services
CC Park & RecreationVariableParks and recreation services (rate varies by district)
Schools #2 Dayton Enrichment1.3280976799%School district enrichment levy
Schools #2 Capital/Tech Bond1.4724326063%School district bond payments
Pres/Star District Enrichment (#35/37)1.3836412639%Special district enrichment (if applicable)
Pres/Star District Bond (#35/37)0.7651435194%Special district bond payments (if applicable)

Note: Actual rates vary by property location within specific taxing districts. Properties in different school districts or special assessment areas will have different total tax rates. The total county tax collection for 2025 is $1,239,899.70 with special assessment districts contributing an additional $12,434,388.40.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Columbia 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 taxes in Columbia County are triggered by specific property changes that occur during the tax year, primarily new construction, major improvements, or ownership changes that result in a reassessment. When these events occur, the county assessor calculates the difference between the new assessed value and the previous assessment, then applies the current tax rate to determine the supplemental tax amount.

For example, if a property owner completes a $50,000 addition to their home mid-year, and the county's effective tax rate is 2.5% (including all applicable districts), the supplemental tax would be calculated as: $50,000 × 0.025 = $1,250, prorated for the portion of the tax year remaining after completion. Supplemental taxes are billed separately from regular property taxes and have their own due dates.

Example Calculation

Example 1: $300,000 Property Value

  • Assessed Value: $300,000
  • Applicable Tax Credits: $0 (assuming no credits applied)
  • Net Taxable Value: $300,000
  • Tax Rate: 2.5% (example rate including all districts)
  • Annual Tax: $7,500
  • Monthly Escrow: $625

Example 2: $600,000 Property Value

  • Assessed Value: $600,000
  • Senior/Disability Credit Applied: -$1,500 (example, requires application)
  • Net Taxable Value: $598,500
  • Tax Rate: 2.5% (example rate including all districts)
  • Annual Tax: $14,963
  • Monthly Escrow: $1,247

Example 3: $1,000,000 Property Value

  • Assessed Value: $1,000,000
  • Applicable Tax Credits: $0 (high-value properties typically don't qualify)
  • Net Taxable Value: $1,000,000
  • Tax Rate: 2.5% (example rate including all districts)
  • Annual Tax: $25,000
  • Monthly Escrow: $2,083

Note: All tax credits require separate applications and approval. Rates shown are examples as actual rates depend on your property's specific taxing districts.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Columbia County require borrowers to maintain an escrow account for property tax payments. The lender collects monthly payments equal to 1/12th of the annual property tax bill and pays taxes directly to the county when due. Lenders typically collect the first half payment by the April 30th deadline and the second half by October 31st if the property owner chooses the split payment option.

Property owners should verify that their lender has current tax information, especially after reassessments or when tax rates change due to new bond measures or levy adjustments. If your escrow analysis shows a shortage, the lender may increase your monthly payment or require a lump sum payment to cover the deficit. Property owners can request annual escrow analyses from their lenders to ensure adequate funds are being collected.

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 Columbia County for the 2025 tax year? A: The first half is due by April 30, 2025. If you pay the first half on time, the second half is due by October 31, 2025. If you miss the April 30th deadline, the entire annual amount becomes due by October 31st.

Q: What tax credits are available and how do I apply? A: Washington offers property tax credits for seniors, disabled persons, and disabled veterans who meet income and residency requirements. These credits reduce your tax bill but require annual application through the county assessor's office. Contact Columbia County Assessor for specific income limits and application deadlines.

Q: How does the homestead exemption work? A: Washington's homestead exemption is limited to $125,000 for real property and helps protect your home from certain creditor claims, but it does not reduce your property tax bill. This is different from tax credits which do reduce taxes.

Q: When does the county assess property values? A: Columbia County follows Washington state law requiring annual assessment updates. Assessment notices are typically mailed in late spring, with appeal deadlines usually falling in July.

Q: What are the penalties for late payment? A: Late payments incur interest, penalties, and costs as specified in county ordinances. Interest begins accruing immediately after the due date.

Q: Can I pay my property taxes online? A: Contact the Columbia County Treasurer's office for current online payment options and accepted payment methods.

Q: Why do tax rates vary within Columbia County? A: Different areas are served by different school districts, fire districts, hospital districts, and other special purpose districts, each with their own levy rates that are added to the base county rate.

Q: How do I appeal my property assessment? A: Assessment appeals must be filed with the Columbia County Board of Equalization within the specified deadline (typically 30 days after assessment notices are mailed). Contact the county assessor's office for appeal forms and procedures.

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 Tax Levy Sheetcolumbiacountywa.gov
02
Tax Doc
PROPERTY TAX STATISTICS 2025dor.wa.gov
03
County
Property tax ratios by county 2024 for 2025 taxesdor.wa.gov
04
Tax Doc
2023 Tax Levy Sheetcolumbiacountywa.gov
05
Tax Doc
2021 Tax Levy Sheetcolumbiacountywa.gov
06
House Bill Report ESSB 5408lawfilesext.leg.wa.gov
07
Tax Doc
Property tax exemption for seniors, people retired due to ...dor.wa.gov
08
Chapter 84.36 RCW: EXEMPTIONSapp.leg.wa.gov
09
County
Local Rules | Columbia County, WA - Official Websitecolumbiacountywa.gov
10
County
Columbia County - SAO Online Servicesportal.sao.wa.gov
All sources verified as of 2025 Tax Year

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