820 ILCS 193/10

(a) Except as otherwise provided by law, a freelance worker shall be paid the contracted compensation amount on or before the date the compensation is due under the terms of the contract. If the contract does not specify when the hiring party must pay the contracted compensation or the mechanism by which the date will be determined, compensation shall be due no later than 30 days after the completion of the freelance worker's services under the contract. (b) Once a freelance worker has commenced preparation of the product or performance of the services under the contract, the contracting entity shall not require as a condition of timely payment that the freelance worker accept less compensation than the amount of the contracted compensation.