70 ILCS 605/5-24
Any original or additional assessment, installment, or interest on assessments or installments not paid on or before the date on which the same becomes due shall be deemed delinquent. The district collector or collectors on or before the 8th day of September in each year, shall make out a report of (a) any original or additional assessments, (b) any installments of assessments, (c) any annual maintenance assessments and (d) any interest on any assessment against privately owned land or other property, which were not paid when due and have become and remain delinquent and certify the same to the County Collector of the county in which such land or other property is situated.
The County Collector to whom such a report is made shall make return of such delinquencies to the Circuit Court with his return of delinquent general taxes, and proceedings shall be had and notice given with like force and effect as in the collection of delinquent general taxes.
Notwithstanding the report of delinquent assessments to the County Collector or the return thereof by the County Collector to the court, both the district collector and the County Collector are authorized to receive payment of any such delinquent assessments, together with interest, penalties and costs, and may give receipts for the same. The district collector shall keep a memorandum of all such payments received by him, and, on or before the day fixed by the court for the sale of such lands, lots and railroads, he shall present such memorandum to the County Collector, who shall thereupon remove the property from the list of lands to be sold and show such payment upon his books.
At the sale for delinquent assessments, the commissioners may become purchasers, or they may designate some person to attend the sale and bid on the delinquent property as agent for and on behalf of the district. The commissioners may accept a deed from the owner of any real estate upon which an assessment is delinquent.
70 ILCS 605/5-24