820 ILCS 405/2202
If at any hearing held pursuant to Sections 2200 or 2201 before the Director or his duly authorized representative it shall appear that, in a prior proceeding before a claims adjudicator, Referee or the Board of Review, a decision was rendered in which benefits were allowed to a claimant, based upon a finding by such claims adjudicator, Referee or the Board of Review, as the case may be, that (A) the petitioning employing unit is an employer as defined by this Act, or (B) the claimant has rendered services for such employing unit that constitute employment as defined by this Act, or (C) the claimant was paid or earned, as the case may be, any sum that constitutes "wages" as defined by this Act, and that such employing unit was given notice of such prior proceedings and an opportunity to be heard by appeal to such Referee or the Board of Review, as the case may be, in such prior proceeding, and that such decision of the claims adjudicator, Referee or Board of Review allowing benefits to the claimant became final, the aforementioned finding of the claims adjudicator, Referee or the Board of Review, as the case may be, shall be final and incontrovertible as to such employing unit, in the proceedings before the Director or his duly authorized representative, and shall not be subject to any further right of judicial review by such employing unit. If, after the hearing held pursuant to Sections 2200 or 2201, the Director shall find that services were rendered for such employing unit by other individuals under circumstances substantially the same as those under which the claimant's services were performed, the finality of the findings made by the claims adjudicator, Referee or the Board of Review, as the case may be, as to the status of the services performed by the claimant, shall extend to all such services rendered for such employing unit, but nothing in this Section shall be construed to limit the right of any claimant to a fair hearing as provided in Sections 800, 801, and 803.
820 ILCS 405/2202