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Updated 2025 Tax Year

Boise County
Property Tax Guide

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

10 Official Sources
8 min read
Quick Facts
Tax Rate
Varies by taxing district combination, no statewide cap on assessed values
Exemptions
4+ Available
Section 1

How Property Tax Works

Boise County, Idaho operates under the state's property tax system, which funds essential local services including schools, emergency services, road maintenance, and county operations. Property taxes in Boise County are levied annually based on assessed property values and vary significantly by location within the county due to different combinations of special taxing districts such as school districts, fire protection districts, and cemetery districts.

The county follows Idaho's standard assessment practices where properties are assessed at market value without a statewide assessment cap. Property owners in Boise County typically see effective tax rates that vary based on their specific taxing district combination, with rates determined annually through local budget processes. The tax year runs concurrent with the calendar year, and property taxes are a primary funding source for local government services throughout the county.

Section 2

What Makes Up Your Tax Bill

ComponentRate RangeDescription
County GeneralVariesBasic county operations and services
School DistrictsVariesLocal school district operations and bonds
Highway DistrictVariesRoad maintenance and transportation
Fire ProtectionVariesEmergency and fire services (where applicable)
Cemetery DistrictVariesCemetery maintenance (where applicable)
Total Effective Rate~1.0%Varies by specific taxing district combination

Rates shown are estimates for FY 2025. Exact rates vary significantly by location within Boise County based on which special taxing districts serve each property. Contact the Boise County Assessor for your specific tax rate combination.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Boise 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 taxes in Boise County are additional property tax assessments that occur when there are mid-year changes to property ownership, completion of new construction, or significant improvements that weren't captured in the annual assessment. These taxes are calculated based on the difference between the old and new assessed values, prorated for the remaining months in the tax year.

For example, if you complete a $50,000 home addition in March and your local tax rate is 1.2%, you would owe supplemental taxes of approximately $500 ($50,000 × 1.2% × 9/12 months remaining). Supplemental tax bills are issued separately from regular annual tax bills and have their own payment due dates, typically 30 days from the bill date.

Example Calculation

Example 1: $300,000 Home

  • Assessed Value: $300,000
  • Homeowner's Exemption Applied: -$125,000 (requires application)
  • Net Taxable Value: $175,000
  • Annual Tax (at 1.0%): $1,750
  • Monthly Escrow: ~$146

Example 2: $600,000 Home

  • Assessed Value: $600,000
  • Homeowner's Exemption Applied: -$125,000 (requires application)
  • Net Taxable Value: $475,000
  • Annual Tax (at 1.0%): $4,750
  • Monthly Escrow: ~$396

Example 3: $1,000,000 Home

  • Assessed Value: $1,000,000
  • Homeowner's Exemption Applied: -$125,000 (requires application)
  • Net Taxable Value: $875,000
  • Annual Tax (at 1.0%): $8,750
  • Monthly Escrow: ~$729

Note: Homeowner's exemption requires annual application and property must serve as primary residence. Actual rates vary by taxing district location.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Boise County require property tax escrow accounts to ensure timely tax payments. Your lender collects monthly escrow payments along with your mortgage payment, typically 1/12th of your annual property tax bill plus a small cushion. The lender pays your property taxes directly to Boise County when they become due.

Escrow accounts are analyzed annually, and adjustments are made based on actual tax bills versus collected amounts. If your property taxes increase due to assessment changes or rate increases, your monthly escrow payment will be adjusted accordingly. You can request escrow account statements from your lender and should verify that payments are made timely to avoid penalties. Property owners without mortgages or those who've paid off their loans are responsible for making direct payments to the county.

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 Boise County for the current tax year? A: Property taxes are due December 20th annually. If no demand is made, full payment is due by this date. You may also pay in two installments - first half by December 20th and second half by June 20th of the following year.

Q: What homeowner tax credits are available and do they require application? A: The Homeowner's Exemption (Idaho Code 63-602G) provides up to $125,000 reduction in assessed value for primary residences. This exemption REQUIRES annual application and the property must serve as your primary residence.

Q: How does the Homeowner's Exemption work? A: The exemption reduces your property's taxable assessed value by up to $125,000, not the market value. It must be applied for annually and only applies to your primary residence where you live as of January 1st.

Q: When are properties assessed and how can I appeal? A: Properties are assessed annually as of January 1st. Assessment notices are typically mailed in April. You have until the fourth Monday in June to file an appeal with the Boise County Board of Equalization if you disagree with your assessment.

Q: What are the penalties for late payment? A: If taxes aren't paid by December 20th or the second half isn't paid by June 20th, penalties and interest accrue. The county begins the tax deed process in August for delinquent taxes, with final notice that payment must be made by January 31st of the following year.

Q: Can I pay my property taxes online? A: Contact the Boise County Treasurer's office directly for current online payment options and procedures, as systems may vary.

Q: Why do property tax rates vary within Boise County? A: Tax rates depend on which special taxing districts serve your property, including school districts, fire districts, highway districts, and cemetery districts. Each district sets its own levy rate based on local needs and budgets.

Q: What triggers supplemental tax assessments? A: Supplemental taxes are triggered by change of ownership, completion of new construction, or significant property improvements that occur after the January 1st assessment date but during the current tax year.

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