65 ILCS 5/3.1-35-120
A city collector, if one is elected or appointed, shall preserve all warrants returned to the collector and shall keep books and accounts in the manner prescribed by the corporate authorities. All of the collector's warrants, books, and vouchers, and all papers pertaining to the office, may be examined at any time by the mayor, city clerk, or any member or committee of the corporate authorities. Weekly, and oftener if required by the corporate authorities, the collector shall pay over to the treasurer all money collected by the collector from any source, taking the treasurer's receipt in duplicate and filing one of the receipts immediately with the clerk. At that time, or on demand, the clerk shall give the collector a copy of any receipt so filed.
65 ILCS 5/3.1-35-120