Ill. Admin. Code tit. 38 § 210.80
The loan agreement executed by the consumer bearing evidence of indebtedness shall be cancelled and returned to the consumer promptly following the paid in full date or upon cancellation of future payment obligations pursuant to Section 2-25 of the Act. Where original documents are not available, a licensee shall substitute copies reproduced from any medium or format that accurately reproduces the original documents. If an executed copy of a legal document is retained following payment in full or renewal, it must be clearly marked "PAID", "CANCELLED" or "RENEWED", indicating the date of payment or renewal. Copies clearly identified with the legend "COPY NOT NEGOTIABLE" or similar language may be used in lieu of this requirement.
Ill. Admin. Code tit. 38, § 210.80