35 ILCS 200/30-10

The governing body of any taxing district may, by ordinance or resolution, establish a special reserve fund for the purpose of accumulating monies to pay refunds of erroneously or illegally collected taxes. A taxing district establishing a special fund may transfer into the fund each year taxes or monies from the general corporate fund to be used solely for the payment of tax refunds and expenses incident to refunds. The balance of the fund shall not exceed 1/2 of 1% of the equalized assessed valuation of property in the taxing district.