35 ILCS 515/6.1
If a tax bill is in error as to the square footage of the mobile home or as to the rate of tax, the owner may file within 6 months following receipt of the bill an affidavit with the county board of assessors, supervisor of assessments or county assessor setting forth such error. If the tax bill does not show the name of the correct owner, the person whose name appears as owner on the bill may file an affidavit with the county board of assessors, supervisor of assessments or county assessor so stating and identifying the correct owner, if known. Upon the filing of an affidavit as provided in this Section, the county clerk or, in counties in which a county assessor is elected pursuant to Section 3-45 of the Property Tax Code, the county assessor shall issue a corrected bill and shall so indicate on his records.
35 ILCS 515/6.1