Ill. Admin. Code tit. 68, § 1376.55
c) A person seeking restoration of a license after it has expired or been placed on inactive status for more than 5 years shall file an application, on forms supplied by the Division, proof of completion of the CE required under Section 1376.50, and payment of the restoration fee required by Section 1376.65 in the 2 years prior to restoration. The applicant shall also submit one of the following:
3) Evidence of current certification as a BCBA or BCaBA; or
f) Except for persons seeking restoration of a license pursuant to subsections (d) and (e), when the accuracy or sufficiency of any submitted documentation is questioned by the Division because of a lack of information, discrepancies, or conflicts in information given or a need for clarification, the person seeking restoration of a license may be requested to: