This guide is an overview of registering your business for Illinois state payroll taxes. For more support, contact the state agency directly.
This guide includes key payroll tax requirements, links to state agency portals, and instructions for granting third-party access to Wave's partner. These steps are required to complete your tax profile in Wave so we can manage your payroll tax payments and filings on your behalf.
Tax requirements
To pay employees in Illinois, you may need to register for the following taxes:
Illinois state Income Tax Withholding and Unemployment Insurance (UI) Tax
The Withholding and Unemployment Insurance Tax uses a single registration portal.
- Tax agencies: Illinois Department of Revenue (IDOR) and Illinois Department of Employment Security (IDES)
- Registration Portal: Register at MyTax Illinois
During registration, be sure to select both:
- State Income Tax Withholding, and
- Unemployment Insurance (UI) Tax
This ensures that both your Taxpayer ID (IDOR) and Unemployment Account Number (IDES) are assigned through a single application.
Applications may also be submitted by mail or in person. If you choose one of these registration methods, contact the state agency directly for the required forms and instructions.
Third-Party Administrator (TPA) access
To authorize filing on your behalf:
- Log in to MyTax Illinois.
- Navigate to Settings > Manage Third Party Access.
- Set the following:
- Allow = Yes
- Default Access = Third Party
- Default Account Access = Full Access
Complete your payroll tax profile
After completing your registration steps, complete your payroll tax profile. Be sure to update your account with your:
- Taxpayer ID (IDOR)
- Unemployment Account Number (IDES)
Additional Support
For help with your tax account, registration, or technical errors, contact the state agency directly:
- IDOR (Withholding): (217) 785-3707 or REV.DoNotReply@Illinois.gov
- IDES (UI Tax): (800) 247-4984
- IDES Employer Resources
- IL DOR Tax Resources - Business