Electronic Transmitter Information

General Information

The information on this page does not apply to the MeF transmissions for business or individual income tax.

SSL Certificates

The Illinois Department of Revenue is upgrading its Secure Socket Layer (SSL) certificates.  Effective January 1, 2016, only SHA2 certificates will be valid with the Illinois Department of Revenue.  Installing the certificates below will allow you to continue transmitting with the department.

To install the following certificates in the Intermediate Certification Authorities (right click and save as):

L1K Entrust51d360ee10/23/2024
G2 Entrust51d34044 9/22/2024

To install the certificate below in the Trusted Root Certification Authorities (right click and save as):

Root   Entrust456b5054 11/27/2026

SSL certificates are an essential component of the data encryption process that make Internet transactions secure. They are electronic files that provide authentication to protect the confidentiality and integrity of website communication with browsers.

The SSL certificate’s job is to initiate secure sessions with a user’s browser via the secure sockets layer (SSL) protocol. This secure connection cannot be established without the SSL certificate, which digitally connects company information to a cryptographic key.

HttpsPost Utility and User Guide

Illinois Department of Revenue’s HttpsPost Utility program transfers files to and from the Illinois Department of Revenue's (IDOR) Gateway server via the Internet using Secure Socket Layer (SSL) technology. The utility runs as a 32-bit application under Microsoft Windows 95, 98, NT, 2000, XP, 7, and 10. The program supports both a graphical user interface (GUI) mode of operation as well as a command line mode suitable for batch processing.

To install, place the executable file, HttpsPost.exe, in an empty directory or folder on your computer.  You will access this utility each time you are ready to upload files and download acknowledgments. Using an empty directory or folder will provide you with any easy way to keep track of all of your acknowledgment files.
The HttpsPost Utility User Guide provides detailed instruction for the utility.

Helpful Tip

If you have issues getting through your own firewall, below are firewall settings provided by the department’s IT department.

Firewall settings
Webserver IP =
PORT 443 must allow an OUTGOING HTTPPOST

Additional Help

If you have issues transmitting returns, contact the Electronic Commerce Division at 866-440-8680.