55 ILCS 5/6-1005
Except as herein provided, neither the county board nor any one on its behalf shall have power, either directly or indirectly, to make any contract or do any act which adds to the county expenditures or liabilities in any year anything above the amount provided for in the annual budget for that fiscal year. Provided, however, that the County Board may lease from any Public Building Commission created pursuant to the provisions of the Public Building Commission Act, approved July 5, 1955, as heretofore or hereafter amended, any real or personal property for county purposes for any period of time not exceeding twenty years, and such lease may be made and the obligation and expense thereunder incurred without making a previous appropriation therefor, except as otherwise provided in Section 5-1108. Nothing contained herein shall be construed to deprive the board of the power to provide for and cause to be paid from the county funds any charge upon said county imposed by law independently of any action of such board. Except as herein provided, no contract shall be entered into and no obligation or expense shall be incurred by or on behalf of a county unless an appropriation therefor has been previously made.
55 ILCS 5/6-1005