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Possible online services disruption due to Internet related outage

A worldwide technology outage is causing disruption to some State of Illinois online systems.  We are aware of this issue and are diligently working on restoration.

Withholding Income Tax - FSET

Fed/State Employment Taxes Program (FSET) is a program for large employers and payroll companies to electronically file and pay both their federal and Illinois employment taxes. This includes returns and payments for state withholding and unemployment insurance. The program is open to software developers, transmitters, and payroll service providers who will act as "Reporting Agents" (companies that perform payroll services for other businesses). Withholding income taxpayers must use a payroll service provider or develop their own software to participate in FSET. All participants must complete Form IL-8633-B, Business Electronic Filing Enrollment. Once we have received your enrollment form, we will contact you regarding testing.

Electronic Filing Enrollment and Authorization Forms

  • IL-8633-B - Business Electronic Filing Enrollment
  • IL-8655 - Reporting Agent Electronic Services Authorization

Important Filing Information

Beginning with tax year 2020, IL-941 and IL-941-X test cases, schemas, and business rules are located on the FTA's State Exchange System (SES). To request access to the SES, email your contact's name and email address to Once provided SES access, you will need to complete the Illinois Department of Revenue Withholding/Payroll Service Provider Letter of Intent and submit it to to obtain access the test cases, schemas, and business rules.

  • IL-1370 - Federal State Employment Taxes Implementation Guide (FSET) (5.6 Schema Version)

Software developers and transmitters use their IRS EFIN/ETIN, and will be assigned passwords for communication via the IL Business Gateway. Reporting agents select a single electronic signature used to sign all returns and payment authorizations for their clients. Reporting agents must obtain Form IL-8655 from each client before acting on their behalf.

For questions regarding this program, please contact the Electronic Commerce Division at 1 866 440-8680 or email

For Illinois Department of Employment Security file format information refer to