65 ILCS 5/9-3-47

The purchaser or his assignee shall pay all taxes and assessments on real estate sold under the provisions of this Division 3. Notation of such payments shall be made on the docket of the court, and the same shall be repaid if the real estate is redeemed, together with interest at the rate of the greater of 9% per annum or 70% of the prime commercial rate in effect on the date the special assessment ordinance is adopted.