Idaho State Tax Commission

Save Yourself from a Tax Bill: Update Your W-4 Now!

Find out how easy and important it is to update your Idaho income tax withholding!

Quick links!

We urge you to update your paycheck withholding for both federal and state taxes.

New tax laws have changed the calculation for income taxes withheld from your paycheck.

If you don't withhold enough tax, you could have an unexpected tax bill when you file your tax return.

Steps to take NOW:
  1. Use the withholding estimator at to calculate your federal withholding. Update the federal Form W-4 with that information.
  2. Use page 2 of the Form ID W-4 to calculate your Idaho withholding. Fill out Form ID W-4 with that information.
  3. Give both W-4 forms to your employer.
If you owe money with your state tax return:
  • If you pay your income taxes by the April due date, you won't be charged penalty and interest. You can make prepayments using our free QuickPay service.
  • If you can't pay your taxes by the due date, penalty and interest apply. You can request a payment plan to spread out your payments.

Make sure you have the right amount of taxes withheld from your paycheck.


Guidance for retirement and other sources of nonwage income

If you're receiving retirement or other sources of nonwage income:

  1. Determine if the income is taxable in Idaho.
    • See the Idaho Income Tax Instructions for guidance
    • Taxable income can be:
      • Retirement income
      • Interest
      • Dividends
    • Generally, Idaho doesn't tax Social Security income.
  2. If the income is taxable, follow the next steps.

Note: The entity paying the nonwage income might not withhold Idaho tax. It's your responsibility to estimate the tax you'll owe and be prepared to pay it.

If the entity paying the nonwage income will withhold Idaho tax for you:

  1. Use the Form ID W-4 to determine:
    • Your W-4 box 3 filing status
    • Your Idaho allowance
    • Any additional amount to withhold
      • See Form ID W-4 instructions
      • Consider each source of taxable income as a "job"
  2. Use the information to complete a W-4, or use the entity's W-4 substitute

If the entity paying the nonwage income won't withhold Idaho tax for you:

  1. Estimate your income tax for the nonwage income source:
    1. Estimate your annual income for the source
    2. Estimate your tax on the income. Use the 2018 income tax rate table for your return filing status, and find the total tax you'll owe.
  2. Pay the tax you owe.
    • Make estimated payments directly to the Tax Commission
      • Use Form 51, Estimated Payment of Idaho Individual Income Tax (mark the 2018 box), or
      • Use Quick Pay, online (no log-in needed).
    • Pay the tax on or before April 15

Page last updated August 6, 2019. Last full review of page: December 20, 2018.

This information is for general guidance only. Tax laws are complex and change regularly. We can't cover every circumstance in our guides. This guidance may not apply to your situation. Please contact us with any questions. We work to provide current and accurate information. But some information could have technical inaccuracies or typographical errors. If there's a conflict between current tax law and this information, current tax law will govern.