30 ILCS 305/2
Notwithstanding the provisions of any other law to the contrary, any public corporation may agree or contract to pay interest on bonds or other evidences of indebtedness and tax anticipation warrants issued pursuant to law at an interest rate or rates not exceeding the greater of 9% per annum or 125% of the rate for the most recent date shown in the 20 G.O. Bonds Index of average municipal bond yields as published in the most recent edition of The Bond Buyer, published in New York, New York (or any successor publication or index, or if such publication or index is no longer published, then any index of long term municipal tax-exempt bond yields then selected by a governing body), at the time the contract is made for the sale of the bonds or other evidences of indebtedness or tax anticipation warrants. A contract is made with respect to notes or bonds when the public corporation is contractually obligated to issue notes, bonds, or other evidences of indebtedness or tax anticipation warrants to a purchaser who is contractually obligated to purchase them; and, with respect to bonds or notes bearing interest at a variable rate or subject to payment upon periodic demand or put or otherwise subject to remarketing by or for the public corporation, a contract is made on each date of change in the variable rate or such demand, put or remarketing. When bonds or other evidences of indebtedness or tax anticipation warrants are to be issued by a public corporation on a basis which is not tax-exempt under Section 103 of the Internal Revenue Code of 1986, as now or hereafter amended, or successor code or provision, then the interest rate or rates payable thereon shall be determined by substituting 13 1/2% for 9% and 200% for 125% in the first sentence of this Section.
These amendatory Acts of 1971, 1972, 1973, 1975, 1979, 1982, 1983, 1987 and 1988 are not limits upon any home rule unit.
This Act is not a limit with respect to any bonds, notes and other evidences of obligation for borrowed money issued by any public corporation and purchased or otherwise acquired by the Illinois Finance Authority, pursuant to the Illinois Finance Authority Act, and such bonds, notes and other evidences of obligation for borrowed money may bear interest at any rate or rates, and such rate or rates may be established by an index or formula which may be implemented or established by persons appointed or retained therefor, notwithstanding any other provision of law to the contrary.
30 ILCS 305/2