# TAXES 18-56, Idaho State Income Tax Withholding

Published: June 14, 2018

Effective: Pay Period 12, 2018

## Summary

The income tax withholding formula for the State of Idaho will change as follows:

- The annual amount, per exemption allowance, will decrease from $4,050 to $2,960.
- The Single and Married tax tables will change.

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)

- Subtract the nontaxable biweekly Thrift Savings Plan (TSP) contribution from the gross biweekly wages.
- 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.
- 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.
- Multiply the adjusted gross biweekly wages by the number of pay dates in the tax year to obtain the gross annual wages.
- 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

- 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

- 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.
- 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

page from the drop-down menu on the National Finance Center (NFC) homepage. Select the tab and select from the 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

or via the customer service portal.