35 ILCS 516/280
Any person claiming interest or costs under Sections 260 through 275 shall include the claim in his or her petition for sale in error under Section 255. Any claim for interest or costs which is not included in the petition is waived, except interest or costs may be awarded to the extent permitted by this Section upon a sale in error petition filed by the county collector, without requiring a separate filing by the claimant. Any order for interest or costs upon the petition for sale in error shall be deemed to be entered against the county treasurer as trustee of the fund created by Section 275. The fund shall be the sole source for payment and satisfaction of orders for interest or costs, except as otherwise provided in this Section. If the court determines that the fund has been depleted and will not be restored in time to pay an award with reasonable promptness, the court may authorize the collector to pay the interest portion of the award pro rata from those accounts where the principal refund of the tax sale purchase price under Section 255 is taken.
35 ILCS 516/280