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Withholding Income Tax Changes in 2017

Update (July 2017): The Illinois Income Tax rate increased from 3.75 percent (.0375) to 4.95 percent (.0495). The new income tax rate is effective for income received on or after July 1, 2017 (P.A. 100-22). Employers, please ensure that you make appropriate adjustments in calculating Illinois withholding tax for your employees. Tax practitioners, payroll professionals, and software vendors are also responsible for implementing the appropriate changes.

For additional information, see:

  • FY 2018-01, Summary of Illinois Income Tax and Sales Tax Changes from P.A. 100-22
  • FY 2018-03, Withholding Tax Rate and Personal Exemption Amount Changes
  • Booklet IL-700-T, Illinois Withholding Tax Tables (effective July 1, 2017 - December 31, 2017) (Updated July 2017)
  • Form IL-W-4, Employee's Illinois Withholding Allowance Certificate (Updated July 2017)

Reminder of previously announced changes to Illinois withholding income tax: The 2017 return (Form IL-941) requires the reporting of payroll dates and withholding amounts. Also, the annual filing and payment frequency was eliminated.

For additional information about current Illinois withholding tax requirements, see the following:

Employers: In MyTax Illinois, you may verify payment and filing schedule requirements, view messages or letters that have been published to your account, file returns, make payments, report and pay unemployment insurance (UI 3/40 – Contribution and Wage Report)

Report and pay unemployment insurance tax (UI-3/40 - Contribution and Wage Report) through your MyTax Illinois account.