TAXES 18-58, Idaho State Income Tax Withholding

Published: July 11, 2018
Effective: Pay Period 12, 2018

Summary

The income tax withholding formula for the State of Idaho will eliminate the requirements to "add 2" to the number of exemptions claimed by Single filers with one or more withholding allowances.

No action on the part of the employee or the personnel office is necessary.

Tax Formula

State Abbreviation:

ID

State Tax Withholding State Code:

16

Acceptable Exemption Form:

W-4

Basis for Withholding:

State or Federal Exemptions

Acceptable Exemption Data:

S/M, Number of Exemptions

TSP Deferred:

Yes

Special Coding:

None

Additional Information:

If a State income tax certificate has not been processed or a valid State exemption code is not present, the Federal exemptions will be used in the computation of State taxes.

 

Withholding Formula (Effective Pay Period 12, 2018)

  1. Subtract the nontaxable biweekly Thrift Savings Plan (TSP) contribution from the gross biweekly wages.
  2. Subtract the nontaxable biweekly Federal Health Benefits Plan payment(s) (includes dental and vision insurance program and Flexible Spending Account - health care and dependent care deductions) from the amount computed in step 1.
  3. Add the taxable biweekly fringe benefits (e.g., taxable life insurance) to the amount computed in step 2 to obtain the adjusted gross biweekly wages.
  4. Multiply the adjusted gross biweekly wages by the number of pay dates in the tax year to obtain the gross annual wages.
  5. Determine the exemption allowance by applying the following guideline and subtract this amount from the gross annual wages calculated in step 4:

    Exemption Allowance = $2,960 x Number of Exemptions

  6. Apply the taxable income computed in step 5 to the following table to determine the annual Idaho tax withholding:

     

    Single - Tax Withholding Tables

    If the Amount of Taxable Income Is:

    The Amount of Idaho Tax Withholding Should Be:

    Over $0 but not over $12,000

    $0.00

    Over $12,000 but not over $13,504

    1.125% of excess over $12,000

    Over $13,504 but not over $15,008

    $17.00 plus 3.125% of excess over $13,504

    Over $15,008 but not over $16,511

    $64.00 plus 3.625% of excess over $15,008

    Over $16,511 but not over $18,015

    $118.00 plus 4.625% of excess over $16,511

    Over $18,015 but not over $19,519

    $188.00 plus 5.625% of excess over $18,015

    Over $19,519 but not over $23,279

    $273.00 plus 6.625% of excess over $19,519

    Over $23,279

    $522.00 plus 6.925% of excess over $23,279

     

    Married - Tax Withholding Tables

    If the Amount of Taxable Income Is:

    The Amount of Idaho Tax Withholding Should Be:

    Over $0 but not over $24,000

    $0.00

    Over $24,000 but not over $27,008

    1.125% of excess over $24,000

    Over $27,008 but not over $30,016

    $34.00 plus 3.125% of excess over $27,008

    Over $30,016 but not over $33,022

    $128.00 plus 3.625% of excess over $30,016

    Over $33,022 but not over $36,030

    $237.00 plus 4.625% of excess over $33,022

    Over $36,030 but not over $39,038

    $376.00 plus 5.625% of excess over $36,030

    Over $39,038 but not over $46,558

    $545.00 plus 6.625% of excess over $39,038

    Over $46,558

    $1,043.00 plus 6.925% of excess over $46,558

     

  7. Divide the annual Idaho tax withholding calculated in step 6 by the number of pay dates in the tax year and round to the nearest dollar to obtain the biweekly Idaho tax withholding.
  8. Add the additional amount or percentage elected by the employee to the pay period tax calculated in the above step and round to the nearest dollar to determine the amount of tax to be withheld.

Resources

To view the updated tax formula, go to the HR and Payroll Clients page from the MyNFC drop-down menu on the National Finance Center (NFC) homepage. Select the Publications tab and select U.S. Income Tax Formulas from the Publications menu to launch the tax map. Select the desired State from the map provided for the formula.

Inquiries

For questions about NFC processing, authorized Servicing Personnel Office representatives should contact the NFC Contact Center at 1-855-NFC-4GOV (1-855-632-4468) or via the customer service portal.