35 ILCS 200/14-40
If the tax or assessment on property liable to taxation is prevented from being collected for any year or years, by a reason other than administrative error, the amount of the tax or assessment which should have been paid may be added to the tax on the property for any subsequent year, in columns designating the year or years. "Administrative error" includes but is not limited to failure to include an extension for a taxing district on the tax bill, an error in the calculations of tax rates or extensions or any other mathematical error by the county clerk, or a defective coding by the county, but does not include a failure by the county to send a tax bill to the taxpayer, the failure by the taxpayer to notify the assessor of a change in the tax-exempt status of property, or any error concerning the assessment of the property.
35 ILCS 200/14-40