35 ILCS 200/21-215 : Government — Revenue — Property Taxes — Property Tax Code — Due Dates, Delinquencies, And Enforcement Of Payments — Annual tax sale procedure —215 - Penalty bids

The person at the sale offering to pay the amount due on each property for the least penalty percentage shall be the purchaser of that property. No bid shall be accepted for a penalty exceeding 9% of the amount of the tax or special assessment on property.