35 ILCS 750/1-25: Time period of lien.

(a) A notice of tax lien shall be a lien upon the debtor's personal property, both tangible and intangible, located anywhere in the State, and a lien upon the real property of the debtor located in the county or counties as specified in the notice of tax lien, for a period of 20 years from the date of filing unless it is sooner released by the Department.

(b) A notice of release of tax lien filed in the registry shall constitute a release of the tax lien within the Department, the registry, and the county in which the tax lien was previously filed. The information contained on the registry shall be controlling, and the registry shall supersede the records of any county.