Illinois State Income Tax Withholding Information
State Abbreviation: |
IL |
State Tax Withholding State Code: |
17 |
Acceptable Exemption Form: |
IL-W-4 |
Basis for Withholding: |
State Exemptions |
Acceptable Exemption Data: |
0/Number of Regular Allowances/Number of Additional Exemptions |
TSP Deferred: |
Yes |
Special Coding: |
Determine the Total Number of Allowances field as follows: First Position - Enter 0 (zero). Second or Third Positions - Enter the number of exemptions claimed. Determine the Additional Exemptions Claimed field as follows: First and Second Positions - Enter the number of additional allowances claimed on Line 2 of the IL-W-4. Valid values are 00 through 99. If no allowances are claimed, enter 00. |
Additional Information: |
None |
Additional Resources: |
Withholding Formula (Effective Pay Period 06, 2015)
- Subtract the nontaxable biweekly Thrift Savings Plan 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 (i.e., taxable life insurance) to the amount computed in step 2 to obtain the adjusted gross biweekly wages.
- Multiply the adjusted gross biweekly wages times 26 to obtain the annual wages.
- Determine the exemption allowance by applying the following guideline and subtract this amount from the annual wages.
Exemption Allowance = $2,150 x Number of Exemptions
- Determine the additional allowance by applying the following guideline and subtract this amount from step 5 to compute the taxable income.
Additional Allowance = $1,000 x Number of Additional Exemptions
- Multiply annualized taxable wages by 3.75 percent to determine the annual tax.
- Divide the annual Illinois tax withholding by 26 to obtain the biweekly Illinois tax withholding.