Illinois Payroll Tax Filing Requirements
TaxZerone makes Illinois payroll tax filing simple for employers. Explore everything you need to know about Illinois payroll tax forms, filing schedules, and employer requirements — all in one place to help you stay compliant and on time.
Illinois Employer Payroll Tax Filings
Employers in Illinois are required to file both withholding tax and unemployment insurance (UI) tax reports. Below are the key Illinois payroll tax forms and their due dates to stay compliant with state filing requirements.
Employer Payroll tax forms:
Information return:
Illinois Unemployment Tax (SUI)
In Illinois, employers must pay State Unemployment Insurance (SUI) taxes to fund benefits for eligible unemployed workers. The contribution rate depends on your assigned tax rate and the taxable wage base.
| Illinois UI Tax Rates (2025) | |
|---|---|
| Taxable Wage Base | $13,916 |
| Experienced employer rates | 0.75% to 7.85% |
| New employer rate | 3.65% |
UI Tax Form and Due Dates
| Form Name | Due Date |
|---|---|
| Form UI-3/40 | Q1: April 30 Q2: July 31 Q3: October 31 Q4: January 31 |
How does TaxZerone help you file?
TaxZerone makes tax filing effortless by supporting all essential federal forms and offering clear guidance for state filings—helping you file accurately, stay compliant, and avoid costly penalties.
Frequently Asked Questions
1. What payroll tax forms do Illinois employers need to file?
Illinois employers must file Form IL-941 to report income tax withheld from employee wages. They must also complete New Hire Reporting (Form NHR) for all new or rehired employees and may need to file unemployment insurance contribution reports with the Illinois Department of Employment Security (IDES).
2. How do employers submit payroll tax forms in Illinois?
Employers submit Illinois payroll tax forms, including Form IL-941, electronically through MyTax Illinois, the official online filing system of the Illinois Department of Revenue (IDOR).
3. How do I correct an error on a previously filed Form IL-941?
If you discover an error, you must file an amended Form IL 941-X to make corrections. Be sure to explain the reason for the amendment and include any additional tax due.