Rate Breakdown

Property taxes in Bonneville County are calculated by multiplying the assessed value (minus exemptions) by the total local millage rate.

How Property Tax Works in Bonneville County

In Bonneville County, property taxes are assessed annually by the local assessor’s office. The process begins with a property valuation, which considers the market value of the real estate as of November 1 of the previous year. Once the value is established, the county applies the applicable millage rates—expressed in mills (1,000 mills = 1%)—to calculate the tax owed. The total millage rate in Bonneville County is a combination of the county rate, the City of Ashton rate (if applicable), school district rates, and any special district levies. The assessed value multiplied by the total millage rate gives the annual tax liability.

Available Exemptions

Bonneville County residents can reduce their taxable base through several exemptions available statewide in Idaho. These include:

• Homestead Exemption: Provides up to $10,000 in taxable value reduction for qualified primary residences.
• Senior Citizen Exemption: Eligible homeowners aged 65 or older may receive a $5,716 exemption if annual income is below the state threshold.
• Disability Exemption: Disabled individuals or their spouses can obtain a $3,361 exemption if they meet income and disability criteria.
• Veteran Exemption: Active duty and retired veterans can claim a $7,000 exemption if they are living in Idaho and meet service requirements.

Applicants must submit the appropriate exemption forms to the Bonneville County Tax Assessor before the state‑mandated deadline, which is generally March 31 of the tax year.

Payment Schedule & Deadlines

Bonneville County allows two installment options to ease the tax‑payment burden:

• Full Payment: All unpaid taxes are due by May 1 with no penalties.
• Partial Installment: A partial payment of at least 50% is required by March 1, with the balance due by May 1. If the partial payment is less than 50%, a penalty will be assessed.

Failing to pay by the deadlines results in a penalty of 10% of the unpaid amount, followed by a 15% interest charge per year. Excessive delinquency can lead to tax liens and eventual property foreclosure. To avoid these consequences, most taxpayers choose the installment plan, ensuring no penalties accumulate.

Appealing Your Assessment

If you believe your property's assessed value is inaccurate, you can file an appeal with Bonneville County’s Assessment Appeals Board. The process requires:

• Submitting a written appeal within 60 days of receiving the assessment notice.
• Providing supporting documentation such as recent appraisals, comparable sales, or repair receipts.
• Paying a filing fee, which varies depending on the property type.

The board will review the evidence and hold a public hearing if necessary. A decision is typically issued within 45 days. Appeals are often successful when the assessment exceeds the market value by a significant margin, so keeping thorough records and timely action significantly improves your chances of a favorable outcome.