Idaho state tax has three main pieces: a flat 5.3% individual income tax on taxable income above a built-in zero-tax threshold, a 6% statewide sales and use tax, and property taxes that counties assess and collect under state rules. The Idaho State Tax Commission administers the income and sales taxes and sets the framework counties follow for property tax.
Individual Income Tax
Idaho taxes individual income at a flat 5.3%. The first slice of taxable income is taxed at zero: $2,500 for single filers and $5,000 for married couples filing jointly. Everything above that threshold is taxed at 5.3%.1Idaho State Legislature. Idaho Code 63-3024 – Individuals Tax and Tax Rate
If you are an Idaho resident required to file a federal return, you also have to file an Idaho return. Part-year residents and nonresidents must file when their gross income from Idaho sources is more than $2,500.2Legal Information Institute. Idaho Admin Code 35.01.01.801
Your Idaho return begins with federal adjusted gross income. From there you apply Idaho-specific adjustments: add back things like out-of-state municipal bond interest, and subtract items Idaho doesn’t tax. Social Security benefits are one of those subtractions. Idaho does not tax Social Security at all, so any amount included in your federal income comes back out on the state return.3Idaho State Tax Commission. Income Tax for Seniors and Retirees
Standard Deduction and Federal Conformity
Idaho generally conforms to the federal Internal Revenue Code, so most federal deductions and adjustments carry over. In 2025, House Bill 559 conformed Idaho to the federal One Big Beautiful Bill Act, which brought in larger standard deduction amounts, an enhanced senior deduction, and new deductions for qualified tips, car loan interest, and overtime pay.4Idaho State Tax Commission. Update on Filing 2025 Idaho Income Taxes Now That Conformity Is Law
Because Idaho’s standard deduction tracks the federal amount, you can generally expect the same deduction on both returns. If you itemize federally, you itemize on your Idaho return too.
Filing Deadline and Extensions
Your Idaho individual return and any tax owed for the 2025 tax year are due April 15, 2026.5Idaho State Tax Commission. Individual Income Tax Filing and Paying
Idaho’s extension is automatic, but conditional on how much you have already paid by April 15. To qualify, you must have paid at least 80% of the tax you owe for 2025, or 100% of your total 2024 tax, by the original deadline.6Idaho State Tax Commission. More Guidance on Conformity Deductions and Filing 2025 Idaho Income Taxes A valid extension pushes your filing deadline to October 15. It does not extend the deadline to pay, and interest runs on any unpaid balance from April 15 forward.5Idaho State Tax Commission. Individual Income Tax Filing and Paying
Who Counts as an Idaho Resident
Idaho taxes residents on their worldwide income and nonresidents only on Idaho-source income. Residency turns on where you keep your permanent home and how long you spend in the state. If you are domiciled outside Idaho but physically present in Idaho for more than 270 days in a calendar year, Idaho treats you as a resident for tax purposes.7Idaho State Tax Commission. Specific Circumstances of Residency
Going the other direction is harder. To lose Idaho resident status, you must be outside Idaho for at least 445 days within a 15-month period. After that, spending more than 60 days in Idaho in a calendar year puts you back on the resident rolls.7Idaho State Tax Commission. Specific Circumstances of Residency
Part-year residents report income earned while living in Idaho plus any Idaho-source income earned while living elsewhere. Nonresidents report only Idaho-source income, such as wages for work performed in Idaho or income from Idaho property. Both groups file Form 43.8Idaho State Tax Commission. Form 43 Part-Year Resident and Nonresident Income Tax Return 2025 Instructions
Sales and Use Tax
Idaho charges 6% sales tax on most goods and some services. Taxable transactions include sales, leases, and rentals of tangible personal property, digital media such as books, videos, music, and games, short-term lodging of 30 days or less, prepared meals, event admissions, and recreational facility use.9Idaho State Tax Commission. Sales and Use Taxes Basics Guide
Use tax applies at the same 6% rate when you buy from an out-of-state seller that didn’t collect Idaho sales tax, such as an untaxed online purchase. If you paid sales tax to another state at a lower rate, you owe Idaho the difference.9Idaho State Tax Commission. Sales and Use Taxes Basics Guide
Designated resort cities, smaller communities where tourism drives much of the economy, may add a local sales tax on top of the state rate; some add up to 2.5%. These local additions apply only within the resort city limits, so 6% is the rate across most of the state.
Groceries and the Food Tax Credit
Idaho is one of the few states that applies full sales tax to groceries, but several categories are exempt. Prescription drugs, medical equipment, prosthetic devices, hearing aids, eyeglasses, insulin and diabetes testing supplies, and durable medical equipment are exempt when bought with a practitioner’s prescription or work order.10Idaho State Tax Commission. Introduction to Medical Products Exemption
To offset grocery tax, Idaho gives residents a food tax credit. Most residents qualify for $155 per person. If you save your grocery receipts and submit them with your return, the credit can rise to as much as $250 per person. You can claim the credit even if you aren’t otherwise required to file an income tax return, provided you are an Idaho resident and submit the claim form.11Idaho State Tax Commission. Idaho Food Tax Credit
Property Tax
Property taxes are administered by counties, but state law sets the rules. Each county assessor sets the market value of every property in the county every year. Unless a specific exemption applies, property must be assessed at 100% of market value.12Idaho State Legislature. Idaho Code 63-105 – Powers and Duties — General
Homeowner’s Exemption
If you own and occupy your home as a primary residence, the homeowner’s exemption cuts your taxable value by the lesser of 50% of the assessed value or $125,000, plus up to one acre of land. The home must be your primary residence as of January 1 of the tax year. You apply once; the exemption renews automatically each year unless your ownership or occupancy changes.13Idaho State Legislature. Idaho Code 63-602G – Property Exempt From Taxation — Homestead
Property Tax Reduction (Circuit Breaker)
Idaho’s Property Tax Reduction program can trim your property tax bill by $250 to $1,500 on your home and up to one acre. To qualify for a 2026 reduction, you must meet all three conditions:
- Your total 2025 income, after deducting medical expenses, was $39,130 or less.
- In 2026, you are at least 65, blind, widowed, disabled, a former prisoner of war or hostage, or a parentless child under 18.
- You owned and lived in an Idaho home as your primary residence before April 15, 2026, and the property has a current homeowner’s exemption.
Applications for the 2026 reduction must be filed between January 1 and April 15, 2026. Residents in a care facility or nursing home may also qualify.14Idaho State Tax Commission. Property Tax Reduction
Retirees and Pension Income
Beyond leaving Social Security untaxed and offering the food tax credit, Idaho gives a retirement benefits deduction for specific qualifying pensions. It’s limited: eligible pensions are those under the federal Civil Service Retirement System (CSRS) or Foreign Service Retirement and Disability System (FSRDS), and certain Idaho public-employee pensions under PERSI. You generally must be at least 65, or at least 62 and disabled, and file jointly if married.15Idaho State Tax Commission. Idaho Retirement Benefits Deduction
Retired military members may also qualify if they are classified as disabled, are 62 or older, or are under 62 and had sufficient employment income during the year. A surviving spouse receiving a deceased spouse’s qualifying pension can claim the deduction, provided they have not remarried.15Idaho State Tax Commission. Idaho Retirement Benefits Deduction Maximum deduction amounts are recalculated each year; check the current year’s individual income tax instructions for the limit.
Business Income Tax
Corporations doing business in Idaho pay a flat 5.3% on taxable income, the same rate as individuals. Every corporation, including those incorporated elsewhere, owes a minimum $10 permanent building fund tax each year, even in a loss year. A unitary group pays $10 for each corporation required to file in Idaho.16Idaho State Tax Commission. Business Income Tax Basics
Pass-through entities like LLCs and S corporations don’t pay the corporate tax directly. Income passes through to the owners, who report it on their personal Idaho returns at 5.3%. The entity still files an information return with the Tax Commission.
Penalties and Interest
If you file or pay late, the Idaho State Tax Commission applies one of several penalties depending on what happened:
- Late filing: 5% of the unpaid tax per month, up to 25%.
- Late payment after filing on time: 0.5% of the unpaid tax per month, up to 25%.
- No valid extension and late payment: 2% per month from the original due date until paid.
- Substantial understatement: 10% of the understated amount.
- Fraud: 50% of the unpaid tax.
Interest runs on any unpaid balance from the original due date until the tax is paid. The rate is set by the Tax Commission and changes year to year.17Idaho State Tax Commission. Interest and Penalties