20 ILCS 2505/2505-205

Consistent with rules adopted by the Department, a person may transmit, by facsimile, any return or document required to be filed with the Department under any Act administered by the Department. A signature on a return or other document filed in accordance with regulations promulgated by the Department and transmitted by facsimile is prima facie evidence for all purposes that the document was actually signed by the person whose signature appears on the facsimile.