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Reminder – July 13 Paycheck Includes New Idaho Tax Withholding Rates

Recent tax laws mean significant changes to your withholding and the taxes you owe when you file your 2018 income tax return.  The State Tax Commission recommends that all employees review and update their Form W-4 withholding allowances for both federal and state taxes.

Make sure you have the right amount of taxes withheld from your paycheck. Act now to avoid a tax surprise later.

Follow the steps in this worksheet to ensure you have the correct amount of federal and state tax withholdings. Having too little tax withheld can result in penalties and interest when you file your 2018 return. Having too much income tax withheld can mean less money in your paycheck.

Federal – Use the IRS withholding calculator or the Form W-4 instructions to estimate your federal withholding. Changes may be made on a paper Form W-4 or through PeopleSoft Self Service.

State – Use the 2018 W-4 Worksheet for Idaho to estimate your Idaho withholding.  For further guidance, please watch this video about using this worksheet. Using the federal allowance number for Idaho could cause miscalculations to your Idaho withholding, so it’s best to calculate both separately. State withholding changes can only be made and submitted on a paper Form W-4.*

Forms may be sent to Boise State’s Human Resources in three ways:

  1. Via interoffice mail to Human Resources at MS-1265
  2. Dropped off at Human Resources, 2225 W. University Drive, Capitol Village No. 3
  3. Mailed to Human Resources, 1910 University Drive, Boise, Idaho 83725-1265

Because this new law impacts all employees working within the State of Idaho, please share this information with family and friends.

*Note: Idaho doesn’t have a separate W-4 form at this time, so you should list both federal and state withholding allowances on the federal W-4 form.  The 2018 W-4 Worksheet for Idaho has instructions on page 1 on how to do this, and page 4 has a sample of an updated W-4. The State Tax Commission website includes guidance for retirement and other non-wage income.

Links to Federal and State Resources:

Federal Tax Resources –

  •         IRS withholding calculator to estimate your federal withholding
  •         Form W-4, Employee’s Withholding Allowance Certificate

State Tax Resources – State of Idaho Tax Commission:

  •         2018 W-4 Worksheet for Idaho
  •         Recorded video on how to use the 2018 W-4 Worksheet for Idaho
  •         Retirement and other sources of income guidance

For Questions:

Idaho State Tax Commission, Taxpayer Services:

(208) 334-7660 in the Boise area or toll-free at (800) 972-7660