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Updated 2025 Tax Year

King County
Property Tax Guide

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

10 Official Sources
8 min read
Quick Facts
Tax Rate
Approximately 1.8% effective rate (varies by taxing entities - city, school district, county, special districts)
1st Due
Jan 31
Exemptions
6+ Available
Section 1

How Property Tax Works

King County, Texas operates under the state's property tax system, which serves as the primary funding mechanism for local government services including schools, county operations, municipal services, and special districts. Property taxes in King County fund essential services such as education, law enforcement, fire protection, road maintenance, and other community infrastructure. The county follows Texas Property Tax Code regulations, with property assessments conducted annually by the local appraisal district.

Effective property tax rates in King County typically range around the state average of approximately 1.8%, though actual rates vary significantly by location within the county due to different combinations of taxing entities. Your specific tax rate depends on which city, school district, and special taxing districts (such as water districts, emergency services districts, or municipal utility districts) serve your property. The county's rural nature means that many properties are served by different combinations of these taxing entities, resulting in varying effective tax rates across different areas of King County.

Property owners should note that King County's 2025 tax rates are typically finalized by October 15 each year, and final rates may differ from preliminary estimates. The assessment and collection process follows Texas state guidelines, with the King County Appraisal District responsible for property valuations and various taxing entities responsible for setting their respective tax rates.

Section 2

What Makes Up Your Tax Bill

Note: 2025 tax rates for King County are not yet finalized. Rates are typically adopted by October 15 each year. The following represents typical taxing entity components that may apply to properties in King County:

ComponentEstimated Rate RangeDescription
County General Fund$0.35-0.45 per $100King County operations, law enforcement, roads
School District$1.00-1.30 per $100Local school district operations and debt service
City/Municipal$0.15-0.50 per $100City services (varies by municipality)
Emergency Services District$0.05-0.15 per $100Fire protection and emergency medical services
Water/Utility Districts$0.10-0.40 per $100Water, sewer, drainage infrastructure
Hospital District$0.10-0.25 per $100Public healthcare services
Total Estimated Range$1.75-3.05 per $100Combined effective rate varies by location

Rates shown are estimates per $100 of assessed value. Your actual tax rate depends on which specific taxing entities serve your property location. Contact the King County Appraisal District for current year rates applicable to your specific property address.

Section 3

When Are Property Taxes Due?

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

First Installment
Jan 31
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

Texas does not typically issue supplemental tax bills like some other states. Instead, King County follows Texas Property Tax Code provisions where property tax obligations are generally established once per year based on the January 1st assessment date. However, certain situations can affect your annual tax bill or create additional obligations.

New construction or improvements completed after the January 1st assessment date are typically captured in the following year's assessment. If you purchase property or complete major improvements during the tax year, you may be responsible for taxes based on the current year's assessment at the time of closing, with any adjustments handled through the closing process rather than supplemental billing.

For example, if you purchase a home in King County in June that was assessed at $400,000 in January with a combined tax rate of 2.5%, your annual tax obligation would be $10,000 ($400,000 ÷ 100 × 2.5). The closing process would typically prorate this amount between the buyer and seller based on the closing date, but no separate supplemental bill would be issued. Any improvements made after purchase would be reflected in the following year's assessment cycle.

Example Calculation

The following examples use estimated tax rates and available tax credits. Actual rates and credits vary by location within King County and require applications where noted.

Example 1: $300,000 Home

  • Market Value: $300,000
  • Homestead Exemption (School): -$100,000 (requires application)
  • Taxable Value for School: $200,000
  • Taxable Value for Other Entities: $300,000
  • Combined Tax Rate: ~2.2%
  • Annual Tax: ~$5,800
  • Monthly Escrow: ~$483

Example 2: $600,000 Home

  • Market Value: $600,000
  • Homestead Exemption (School): -$100,000 (requires application)
  • Taxable Value for School: $500,000
  • Taxable Value for Other Entities: $600,000
  • Combined Tax Rate: ~2.2%
  • Annual Tax: ~$12,400
  • Monthly Escrow: ~$1,033

Example 3: $1,000,000 Home

  • Market Value: $1,000,000
  • Homestead Exemption (School): -$100,000 (requires application)
  • Taxable Value for School: $900,000
  • Taxable Value for Other Entities: $1,000,000
  • Combined Tax Rate: ~2.2%
  • Annual Tax: ~$20,600
  • Monthly Escrow: ~$1,717

Note: These calculations use estimated rates and assume standard homestead exemption only. Additional exemptions may be available for seniors (65+), disabled persons, or veterans and require separate applications with specific deadlines.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in King County require property tax escrow accounts for borrowers with less than 20% down payment, though some lenders may require escrow regardless of down payment amount. Your lender collects monthly escrow payments along with your mortgage payment, typically 1/12 of your estimated annual property tax bill plus insurance premiums.

Property taxes in Texas are generally due January 31st for the previous year's assessment. Your lender will pay the tax bill directly to the appropriate tax collector when due. Lenders typically conduct annual escrow analyses to ensure adequate funds are collected, which may result in escrow payment adjustments if your property taxes increase or decrease significantly.

If you don't have an escrow account, you are responsible for paying property taxes directly. King County area taxing entities may offer split payment options, but the standard due date is January 31st. You should verify specific payment schedules with each taxing entity, as some may offer discount periods for early payment. Always confirm payment methods, addresses, and deadlines with the King County Tax Assessor-Collector or relevant taxing entity, as requirements can vary between different districts serving your property.

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 King County? A: Property taxes are typically due January 31st for the previous assessment year. Some taxing entities may offer early payment discounts or split payment options. Contact the King County Tax Assessor-Collector for specific due dates and payment options for your property's taxing entities.

Q: What homestead tax credits are available and do I need to apply? A: The primary homestead benefit is a $100,000 school district exemption for your primary residence, which reduces your taxable value for school district taxes only. This exemption requires a one-time application with the King County Appraisal District. Additional exemptions may be available for seniors (65+), disabled persons, or veterans, each requiring separate applications with specific deadlines.

Q: How does the homestead exemption cap work? A: Texas homestead properties benefit from a 10% annual assessment increase cap, meaning your home's assessed value for tax purposes cannot increase more than 10% per year, even if market value increases more. This cap applies automatically once you receive homestead exemption status but does not reduce your property's market value - it limits assessment growth for tax calculation purposes.

Q: When do I need to apply for exemptions and what's the deadline? A: Exemption applications are generally due before May 1st of the tax year. Homestead exemptions typically need to be filed only once and remain in effect while you own and occupy the property as your primary residence. Senior, disability, and veteran exemptions may require periodic re-verification and have specific application requirements and deadlines.

Q: How often are properties assessed and can I appeal? A: Properties are assessed annually as of January 1st. The King County Appraisal District conducts these assessments and mails notices typically by April. If you disagree with your assessment, you can file an appeal with the appraisal review board. Appeal deadlines are typically 30 days from the notice date, or by May 15th, whichever is later.

Q: What are the penalties for late property tax payment? A: Late payment penalties in Texas typically begin February 1st and increase monthly. Penalties generally start at 6% for February payments, 7% for March, 8% for April, and continue increasing. Interest also accrues on unpaid taxes. Specific penalty schedules may vary by taxing entity, so contact the tax collector for exact penalty calculations.

Q: Can I pay my property taxes online? A: Many King County area taxing entities offer online payment options, though availability varies by specific tax collector. Contact the King County Tax Assessor-Collector or your specific taxing entities to confirm online payment availability, accepted payment methods, and any associated convenience fees for electronic payments.

Q: Why do special district taxes vary so much across King County? A: King County includes multiple municipalities, school districts, water districts, emergency service districts, and other special purpose districts that each set their own tax rates. Your specific tax rate depends on which combination of these districts serves your property location. Rural properties may be served by different combinations of districts than properties in incorporated areas, resulting in significant rate variations across the county.

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