TAXES 18-28, Idaho State Income Tax Withholding | National Finance Center

TAXES 18-28, Idaho State Income Tax Withholding

Published: March 21, 2018
Effective: Pay Period 20, 2017

Summary

This tax bulletin is being updated to remove the number of pay periods in steps 4 and 7 and replace with the phrase "number of pay dates in the tax year," thereby preventing any confusion in future years. All other information in this bulletin remains the same.

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 20, 2017)

  1. Subtract the nontaxable biweekly Thrift Savings Plan 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 (i.e., 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 step 4:

    Exemption Allowance = $4,050 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 $2,300

    $0.00

    Over $2,300 but not over $3,772

    1.6% of excess over $2,300

    Over $3,772 but not over $5,245

    $24.00 plus 3.6% of excess over $3,772

    Over $5,245 but not over $6,717

    $77.00 plus 4.1% of excess over $5,245

    Over $6,717 but not over $8,190

    $137.00 plus 5.1% of excess over $6,717

    Over $8,190 but not over $9,662

    $212.00 plus 6.1% of excess over $8,190

    Over $9,662 but not over $13,343

    $302.00 plus 7.1% of excess over $9,662

    Over $13,343

    $563.00 plus 7.4% of excess over $13,343

    Married - Tax Withholding Tables

    If the Amount of Taxable Income Is:

    The Amount of Idaho Tax Withholding Should Be:

    Over $0 but not over $8,650

    $0.00

    Over $8,650 but not over $11,594

    1.6% of excess over $8,650

    Over $11,594 but not over $14,540

    $47.00 plus 3.6% of excess over $11,594

    Over $14,540 but not over $17,484

    $153.00 plus 4.1% of excess over $14,540

    Over $17,484 but not over $20,430

    $274.00 plus 5.1% of excess over $17,484

    Over $20,430 but not over $23,374

    $424.00 plus 6.1% of excess over $20,430

    Over $23,374 but not over $30,736

    $604.00 plus 7.1% of excess over $23,374

    Over $30,736

    $1,127.00 plus 7.4% of excess over $30,736

  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 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.