Last updated: December 17th, 2025
Each state has unique income tax withholding rules. Below are Idaho's 2026 withholding instructions, including allowance calculations, standard deduction adjustments, and the percentage method for determining tax due.
Employers must also adhere to federal income tax withholding rules. More information can be found here about federal rates.
Alternatively, employers can automatically calculate payroll withholding by using ezPaycheck.
| State Abbreviation | ID |
|---|---|
| State Tax Withholding State Code | 16 |
| Acceptable Exemption Form | W-4 |
| Basis For Withholding | State or Federal Allowances |
| Acceptable Exemption Data | S, M / Number of Allowances |
| TSP Deferred | Yes |
| Special Coding | None |
| Additional Information | If a state income tax certificate has not been processed or if a valid state allowance code is not present, the Federal allowances will be used in the computation of state tax. |
| Official State Tax Website | Visit Official Website |
Idaho's ID W-4 (created when federal allowances disappeared) focuses on dependent allowances. Idaho no longer uses allowances for the taxpayer or spouse. Instead, a married couple filing jointly designates one spouse to claim all allowances for their qualifying dependents/children, and the other spouse claims zero. The allowance count is largely tied to Idaho's child tax credit (e.g., one allowance per qualifying child). There are no additional state allowances for being over 65 or blind on the Idaho form (personal exemptions were eliminated in Idaho's tax law).
| Component | Allowances | Notes |
|---|---|---|
| Dependent Allowances | 1 per qualifying child | One spouse claims all dependent allowances |
| Other Spouse | 0 allowances | Must claim zero if spouse claims dependents |
Total Allowances = Number of Qualifying Dependents (claimed by one spouse only)
Idaho eliminated personal and spousal allowances. Only dependent allowances are used, and they must be claimed by one spouse only in a married couple filing jointly. No allowances for age 65+ or blindness.
For links to official state tax and revenue websites for all 50 states, visit our State and Local Tax Sites page.
Subtract the nontaxable biweekly Thrift Savings Plan contribution from the gross biweekly wages.
Subtract the nontaxable biweekly Federal Health Benefits Plan payment(s) (includes flexible spending account - health care and dependent care deductions) from the amount computed in step 1.
Add the taxable biweekly fringe benefits (taxable life insurance, etc.) to the amount computed in step 2 to obtain the adjusted gross biweekly wages.
Multiply the adjusted gross biweekly wages times 26 to obtain the annual wages.
Determine the allowance by applying the following guideline and subtract this amount from the annual wages to compute the taxable income.
Allowance = $3,868 × Number of Allowances
Apply the taxable income computed in step 5 to the tax withholding table to determine the annual Idaho tax withholding.
Divide the annual Idaho tax withholding by 26 to obtain the biweekly Idaho tax withholding.
Want to calculate in an easier way? Learn how to calculate Idaho taxes via ezPaycheck below.
Learn More| Withholding Allowance | Annual Amount |
|---|---|
| 1 | $3,868 |
Formula: $3,868 × Number of Allowances
Allowance per allowance.
| If Taxable Income Is | Tax Withholding | ||||
|---|---|---|---|---|---|
| Over | But Not Over | Base | + | Rate | Of Excess Over |
| $0 | $15,000 | $0 | + | 0.00% | $0 |
| $15,000 | and over | $0 | + | 5.30% | $15,000 |
| If Taxable Income Is | Tax Withholding | ||||
|---|---|---|---|---|---|
| Over | But Not Over | Base | + | Rate | Of Excess Over |
| $0 | $30,000 | $0 | + | 0.00% | $0 |
| $30,000 | and over | $0 | + | 5.30% | $30,000 |
ezPaycheck simplifies payroll calculations, including Idaho's withholding rules. Easily compute taxes, generate reports, and print paychecks or tax forms.
We strive to provide accurate and up-to-date Idaho state tax information for 2026. If you notice any discrepancies, errors, or have questions about the tax rates or calculations shown on this page, please contact our support team. We appreciate your feedback and will review and update the information as needed.
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