Illinois Department of Revenue
Electronic Services

Approved Third Party Software Vendors for Withholding Income Tax (WIT) Filers


If you choose to have a third party file your return, the following are vendors who are approved by the department to electronically file withholding tax returns through the FSET program:

  • AccountantsWorld - Payroll Relief AC
    • Complete payroll processing system designed specifically for professional accountant
    • Comprehensive system handles every payroll need, including compliance, electronic payments and more
    • Customizable for any size business in any type of industry.
    • Time-saving features that makes payroll processing fast and easy for accountants and employers.
  • Intuit - QuickBooks Payroll
    • Intuit's #1 small business payroll solution.
    • Helps manage payroll more efficiently through an easy-to-use service.
    • Three primary subscription-based solutions range from help with basic payroll essentials to full-service options.
  • Monchilla -
    • Monchilla provides a complete payroll solution that will save you time and money with employee time tracking, paychecks, direct deposit & benefit management.
    • Monchilla lets you e-File federal payroll taxes, W2, 1099 forms, as well as state payroll taxes, including the IL-501 Employer Deposit Statement and the IL-941 Quarterly Reconciliation, Unemployment Insurance UI 3/40 for the state of Illinois.
    • For more information please visit our website at call 1-800-544-3765
  • Paychex: - Trusted by over a half million American businesses
    • Comprehensive, customized solutions for payroll, HR, retirement and insurance so you can focus on your business.
    • The preferred provider of payroll and retirement services by the American Institute of Certified Public Accountants (AICPA).
    • A dedicated single point-of-contact in your local area which you know by name and trust.
    • Free apps for your mobile device so you and your employees can access your information like paystubs, reports, and retirement balances.
  • PayCycle - Fast, Easy and Accurate Online Payroll for Small Businesses
  • Thomson Reuters CS Professional Suite – Payroll CS 1-800-968-8900
    • Comprehensive and powerful payroll processing system specifically designed for the professional accounting market.
    • Comprehensive calculation capabilities while supporting multiple departments, unlimited pay and deduction items, and multi-state employees and locations.
    • Supports data conversions, data exports, time clock imports, seamless Direct Deposit, federal and state tax form preparation, electronic filing of Forms 940, 941 and 944, and compliance with federally mandated regulations and changes.
    • True integration with other CS Professional Suite Products.
    • For pricing and information, please call a CS Account Representative at (800) 968-8900 or email
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