Illinois Payroll Tax and Registration Guide
Employers in the Prairie State: learn about Illinois payroll tax and registration here.
Account Number(s) Needed:
Companies who pay employees in Illinois must register with the IL Dept of Revenue to receive an IL Taxpayer ID (with a SEQ number) and a Security Account Number.
IL Dept of Revenue Taxpayer ID Number & Security Account Number: 99-9999999 000 (12 digits, actually the company’s EIN followed by a SEQ number)
- Register online with the Dept of Revenue at MyTaxIllinois using the EIN to obtain a tax account number. You can also use this form.
- Register for ACH Credit Authorization, you can find the instructions here.
- Find an existing Taxpayer ID:
- On Form IL-941, Illinois Withholding Income Tax Return.
- By contacting the IL Dept of Revenue.
Illinois Department of Employment Security Account number: 9999999 9 (7-8 digits)
- Register online with the Department of Employment Security at MyTaxIllinois
- Find an existing Taxpayer ID:
- On Form UI-340, Illinois Employer’s Contribution and Wage Reporting.
- By contacting the IDES.
Required Payroll Documentation:
Withholding
- IL-941 (Illinois Quarterly Withholding Income Tax Return): This report is a good source of information used to balance wages and taxes withheld from prior quarters.
Unemployment
- IL UI 3_40 (Employer’s Contribution and Wage Reporting): This return is a good source of information to use to balance employee gross wages paid and employer contributions made in prior quarters.
Third Party Access /POA Needed:
- No
Local Income Taxes Imposed:
- No
State Resources
Visit state resources for specific tax rates and wage details:
- Dept. of Employment Security for unemployment taxes
- Dept. of Revenue for withholding taxes
