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Updated 2025 Tax Year

Bonneville County
Property Tax Guide

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

10 Official Sources
8 min read
Quick Facts
Tax Rate
0.393% to 0.857% (average 0.702%), varies by taxing districts
Exemptions
4+ Available
Section 1

How Property Tax Works

Bonneville County, Idaho operates under a property tax system that funds essential local services including schools, county government operations, fire protection, and various special districts. Property taxes are the primary funding mechanism for these public services, with tax rates varying significantly based on your property's location within the county due to different combinations of taxing districts.

The county's property tax rates for the 2025 levy year range from 0.393% for rural properties to 0.857% for urban properties, with an overall average rate of 0.702%. However, your actual tax rate depends on which special taxing districts serve your property, such as school districts, fire districts, highway districts, and other local improvement districts. Properties are assessed at 100% of market value as of January 1st each year, and most property tax credits and exemptions require annual application and are not automatically applied.

Section 2

What Makes Up Your Tax Bill

ComponentRate RangeDescription
County GeneralVariesBasic county services and operations
School DistrictVariesLocal school district funding, largest component
Fire DistrictVariesFire protection and emergency services
Highway DistrictVariesRoad maintenance and construction
Cemetery DistrictVariesPublic cemetery maintenance
Other Special DistrictsVariesLibraries, parks, water/sewer, local improvements
Total Urban Rate0.857%Combined rate for urban properties (FY 2025)
Total Rural Rate0.393%Combined rate for rural properties (FY 2025)
County Average0.702%Overall average rate (FY 2025)

Note: Your specific tax rate depends on the combination of taxing districts that serve your property location. Contact the Bonneville County Assessor at 208-529-1320 for your property's exact rate breakdown.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Bonneville 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 Bonneville County are additional property tax bills issued when there are changes to property ownership, new construction completion, or property improvements that increase assessed value during the tax year. These taxes cover the difference between what was originally billed and what should have been billed based on the property changes.

Common triggers include: purchasing a home that hasn't been reassessed at current market value, completing new construction or major renovations, adding structures like garages or pools, or correcting assessment errors. The supplemental tax is calculated by applying the current tax rate to 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 June and your tax rate is 0.702%, your supplemental tax would be approximately $351 ($50,000 × 0.702%) prorated for 7 months (June-December), resulting in a supplemental bill of about $205.

Example Calculation

Example 1: $300,000 Home (Urban Rate)

  • Market/Assessed Value: $300,000
  • Homeowner's Credit Applied: -$1,320 (requires application)
  • Net Taxable Value: $298,680
  • Tax Rate: 0.857%
  • Annual Tax: $2,559
  • Monthly Escrow: $213

Example 2: $600,000 Home (County Average Rate)

  • Market/Assessed Value: $600,000
  • Homeowner's Credit Applied: -$1,320 (requires application)
  • Net Taxable Value: $598,680
  • Tax Rate: 0.702%
  • Annual Tax: $4,203
  • Monthly Escrow: $350

Example 3: $1,000,000 Home (Urban Rate)

  • Market/Assessed Value: $1,000,000
  • Property Tax Reduction Credit: -$1,500 (income-qualified, requires application)
  • Net Taxable Value: $998,500
  • Tax Rate: 0.857%
  • Annual Tax: $8,555
  • Monthly Escrow: $713

Note: All credits require annual application and approval. Actual rates vary by specific taxing districts serving your property.

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Section 5

Escrow & Property Taxes

Most mortgage lenders require property tax escrow accounts for Bonneville County properties, collecting monthly payments along with your mortgage payment to ensure taxes are paid on time. Your lender calculates the monthly escrow amount by dividing your annual property tax bill by 12, often adding a small cushion for potential increases.

Property taxes in Bonneville County become due December 20th each year, when your lender will pay the full amount from your escrow account. If you pay your own taxes, you can split the payment into two installments: pay in full by December 20th, or pay the first half by December 20th and the second half by June 20th of the following year. Your lender will receive the annual tax statement and should provide you with copies for your records.

It's important to verify that your lender is paying the correct amount and on time. You can check payment status online through the Bonneville County Treasurer's website or by calling their office. If you believe your escrow payment is incorrect, contact your lender with a copy of your current tax bill to request an escrow analysis and adjustment.

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 Bonneville County for the current tax year? A: Property taxes are due December 20th each year. You can pay in full by this date, or make a first payment by December 20th and pay the balance by June 20th of the following year. Personal property taxes for businesses are due March 15th.

Q: What property tax credits are available and do I need to apply? A: The main credits include the Homeowner's Credit (reduces taxable value, requires application by April 15th) and the Property Tax Reduction Program/Circuit Breaker (income-qualified credit, requires separate application). Most credits are NOT automatic and must be applied for annually through the County Assessor's office.

Q: How does Idaho's Homestead Credit work? A: Idaho's homestead exemption caps the annual increase in your home's assessed value for property tax purposes, typically limiting increases to 3% per year for owner-occupied primary residences. You must apply with the County Assessor by April 15th annually, and you must occupy the property as your primary residence.

Q: When does the county assess property values and how can I appeal? A: Property values are assessed annually as of January 1st. Assessment notices are typically mailed in April. You have until June 15th to appeal your assessment by contacting the County Assessor's office at 208-529-1320 or filing a formal appeal with the Board of Equalization.

Q: What are the penalties for late property tax payments? A: Delinquent property taxes incur penalties and interest charges. After December 20th, penalties begin accruing monthly. If taxes remain unpaid, the county can eventually place a tax lien on the property and potentially foreclose.

Q: Can I pay my property taxes online? A: Yes, Bonneville County offers online property tax payments through their official website. You can also pay by mail, phone, or in person at the County Treasurer's office. Credit card payments may incur additional processing fees.

Q: Why do property tax rates vary within Bonneville County? A: Tax rates vary based on the special taxing districts that serve your property, such as different school districts, fire districts, highway districts, and local improvement districts. Urban properties generally have higher rates (0.857%) than rural properties (0.393%) due to additional services and districts.

Q: How do special district taxes work? A: Special districts provide specific services like fire protection, road maintenance, libraries, or parks. Each district sets its own levy rate, and your total property tax is the sum of all applicable district rates. You can contact the County Assessor to determine which districts serve your property and their individual rates.

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