Idaho State Income Tax Withholding
Last Updated: January 2026
Overview
Idaho uses a flat income tax rate, having converted from a progressive system effective in 2025. The simplified structure makes withholding calculations straightforward.
2026 Tax Rates
| Tax Type | Rate |
|---|---|
| Flat Tax Rate | 5.3% |
Note: Idaho converted from a progressive tax system to a flat tax in 2025. All taxable income is now taxed at the same 5.3% rate.
Deductions and Exemptions
Idaho uses the federal standard deduction amounts for state tax purposes.
| Filing Status | Standard Deduction |
|---|---|
| Single | Federal amount |
| Married Filing Jointly | Federal amount |
| Head of Household | Federal amount |
Personal Exemption
Idaho does not have a separate state personal exemption. The federal standard deduction is used.
Special Considerations
State W-4 Form
Idaho accepts the federal Form W-4 for state withholding purposes. No separate state form is required.
Flat Tax Conversion
Prior to 2025, Idaho used a progressive tax system. The transition to a flat tax simplified withholding calculations for employers.
No Local Income Taxes
Idaho does not have local income taxes. The state rate applies uniformly across all jurisdictions.
Grocery Tax Credit
Idaho provides a grocery tax credit to residents. This is claimed on the annual tax return and does not affect withholding.
Reciprocal Agreements
Idaho does not have reciprocal tax agreements with neighboring states. However, a credit is available for taxes paid to other states.