35 ILCS 200/20-85
County collectors shall have the same powers and may proceed in the same manner, for the collection of any tax on property, as township collectors. If in any township the office of township collector is or becomes vacant, and the vacancy is not filled on or before the first day of May next following the vacancy, the county clerk shall deliver all the collectors' books to the county collector of the county, having annexed to each book a warrant under the signature and official seal of the county clerk, commanding the county collector to collect from the persons named in the books the sum of taxes charged opposite their names, except as otherwise provided in Section 21-375. The county collector shall then collect and pay over all taxes, assessments and other charges shown in the books, and do all acts required by law as if the taxes, assessments and other charges had been duly returned delinquent by a township collector. The collectors' books so delivered to the county collector shall, for all purposes, in all subsequent proceedings, be used in the same manner and have the same force and effect as if the books were delivered to the township collectors, and returned by them, as provided by law. In the 10 years next following the completion of a general reassessment of property in any county with 3,000,000 or more inhabitants, made under order of the Department, if for any reason the books have not been delivered to the township collector within 5 days after the day specified by the county clerk for that delivery, the county clerk shall deliver the books to the county collector, and all provisions of this Section shall apply. When any injunction restraining the collection of taxes is dissolved after the tax books are returned to the county collector, the taxes or the portion thereof upon which the injunction has been dissolved, shall be paid to the county collector, who shall proceed as though collection of the taxes had never been enjoined.
35 ILCS 200/20-85