735 ILCS 5/13-224
In any action against the State to recover taxes imposed pursuant to Section 2 of the Messages Tax Act, Section 2 of the Gas Revenue Tax Act, Section 2 of the Public Utilities Revenue Act or Section 2-202 of The Public Utilities Act, that were illegally or unconstitutionally collected, or in any action against a municipality to recover taxes imposed pursuant to Section 8-11-2 of the Illinois Municipal Code that were illegally or unconstitutionally collected or in any action against a taxpayer to recover charges imposed pursuant to Sections 9-201 or 9-202 of The Public Utilities Act that were illegally or unconstitutionally collected, the prevailing party shall not be entitled to recover an amount exceeding such taxes or charges paid, plus interest, where applicable, during a period beginning 3 years prior to the date of filing an administrative claim as authorized by statute or ordinance or court complaint, whichever occurs earlier. This provision shall be applicable to all actions filed on or after September 21, 1985.
735 ILCS 5/13-224