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Telecommunications Infrastructure Maintenance Fees

Legal Reference

Electronic Services


Telecommunications infrastructure maintenance fees (TIMFs) are imposed on persons in the business of transmitting, supplying, or furnishing telecommunications and all associated services in Illinois for compensation (i.e., telecommunications retailers).

Tax Rate

Use the Tax Rate Database to determine the rate.

Form/Filing & Payment Requirements

  • Form RT-10, Telecommunications Infrastructure Maintenance Fees Return

The RT-10 is due either monthly or quarterly, based on the taxpayer’s average monthly liability. The department determines how often a return must be filed.

  • A monthly return is due on or before the 30th day of the month following the month for which the return is filed.
  • A quarterly return is due on or before the 15th day of the month following the quarter for which the return is filed.

Form RT-10-X, Amended Telecommunications Infrastructure Maintenance Fees Return

Allowable Deductions and Nontaxable Sales

The following types of telecommunications and associated services are exempt:

  • An addition added to a purchaser’s bill because of:
    • a fee imposed by the tax law
    • a charge under Section 9-221 or 9-222 of the Public Utilities Act
    • a charge under Section 8-11-17 of the Illinois Municipal Code
    • tax imposed by the Telecommunications Excise Tax Act
    • a 911 surcharge
    • tax imposed by Section 4251 of the Internal Revenue Code
    • a tax imposed by the Simplified Municipal Telecommunications Tax Act

  • A charge for a sent collect telecommunication that is received outside of Illinois
  • A charge for leased time on equipment or charges for the storage of data or information or subsequent retrieval or the processing of data or information intended to change its form or content
  • A charge for customer equipment, including such equipment that is leased or rented by the customer, if the charge is separately identified from other charges
  • A charge to business enterprises certified under Section 9-222.1 of the Public Utilities Act, for the extent and period of time specified by the Department of Commerce and Economic Opportunity
  • A charge for telecommunications and all services and equipment provided in connection between a parent corporation and its wholly-owned subsidiaries, or between wholly-owned subsidiaries (and only to the extent that the charge represents expense allocation and not the generation of profit, other than regulatory required profit, for the corporation rendering such services)
  • A bad debt (meaning any portion of a debt that is related to a taxable sale that has become worthless or uncollectible)
  • A charge paid by inserting coins in a coin-operated telecommunication device
  • Wireless telecommunications
  • Sales to federal government

Prepaid telephone calling arrangements (prepaid calling cards) are not subject to Telecommunications Infrastructure Maintenance Fee but are subject to sales tax.


  • Call us at: 1 217 782-5906
  • Mail Form RT-10 and Form RT-10-X to:
    PO BOX 19019
    SPRINGFIELD IL 62794-9019