60 ILCS 1/55-10: Oath or affirmation.

Every person elected or appointed to the office of supervisor, township clerk, assessor, trustee, commissioner of highways, township enforcement officer, or collector, before entering upon the duties of that office, shall take and subscribe, before any person authorized to administer an oath of office, the oath or affirmation of office prescribed by the Constitution. Within 8 days after the oath or affirmation is taken and subscribed, it shall be filed in the office of the township clerk or the clerk of the multi-township board, as the case may be, and the county clerk.