205 ILCS 675/10
A revolving credit plan between a financial institution and a borrower shall be governed by the laws of this State. All terms, conditions and other provisions of and relating to a plan, including, without limitation, provisions relating to the method of determining the outstanding unpaid indebtedness on which interest is applied, time periods within which interest charges may be avoided, change in terms, requirements, rights to charge and collect attorneys' fees, court and collection costs and the computing of periodic interest or charges, shall be and hereby are deemed to be material to the determination of interest applicable to a plan under Illinois law, Section 85 of the National Bank Act and Sections 521 through 523 of the Depository Institutions Deregulation and Monetary Control Act of 1980.
205 ILCS 675/10