35 ILCS 200/21-165
Any person owning or claiming properties upon which application for judgment is applied for and any lienholder of record may, in person or by agent, pay the taxes, and costs due, or in counties with 3,000,000 or more inhabitants, the taxes, special assessments, interest and costs due, to the county collector at any time on or before the business day immediately preceding the day the taxes are sold, and the collector must accept those payments. A home rule unit may not regulate the hours and procedures employed by the county collector in a manner that is inconsistent with this Section. No deadline for the payment of taxes, special assessments, interest, or costs may be imposed by any county, including a home rule unit, if the deadline is inconsistent with this Section. This Section is a limitation under subsection (i) of Section 6 of Article VII of the Illinois Constitution on the concurrent exercise by home rule units of powers and functions exercised by the State.
35 ILCS 200/21-165