50 ILCS 460/55
Pursuant to the Illinois constitutional and statutory provisions relating to intergovernmental cooperation, the county clerk of any county in which property subject to a special assessment is located may, but shall not be required to, agree to mail bills for a special assessment with the regular tax bills of the county, or otherwise as may be provided by a special assessment law. If the clerk agrees to mail such bills with the regular tax bills, then the annual amount due as of January 2 shall become due instead in even installments with each tax bill made during the year in which such January 2 date occurs, thus deferring to later date in the year the obligation to pay the assessments.
If the county clerk does not agree to mail the bills, or if the municipality declines to request the county clerk to mail the bills, the municipality still may bill the annual amount due, as of January 2 , in 2 even installments to become due on or about the due dates for the real estate tax bills issued by the county clerk during the year in which the January 2 date occurs, thus deferring the obligation to pay the assessment installment to later dates in that year.
If the county clerk agrees to mail the bills on behalf of a municipality, the county may charge a fee for such services to be paid from the special assessment. The fee shall be considered as a cost of making, levying, and collecting the assessment provided for in Section 9-2-139 of the Illinois Municipal Code.
50 ILCS 460/55