A property tax lien is a lien or claim for money due to a federal, state, or local government for unpaid and delinquent taxes. For example, the federal government may place a lien on a homeowner’s home or other real property for unpaid federal income taxes, and state and local governments (often counties) may place a lien on real property for unpaid income or property taxes.

The federal, state, or local government entity—also known as a taxing authority—may seek to recover payment for unpaid taxes by forcing the sale of the property on which the lien is placed in the foreclosure process—a process in which the validity of the lien and satisfaction (payment) for the lien is litigated or determined in court.

In Illinois, a property tax lien represents a legal claim against a property for unpaid property taxes. When property taxes are delinquent, the county in which the property is located may place a lien on the property. This lien has priority over most other liens or claims on the property, including mortgages. If the taxes remain unpaid, the county can enforce the lien by selling the property at a public auction, known as a tax sale. The process is governed by state statutes, specifically the Illinois Property Tax Code. The winning bidder at the tax sale receives a certificate of purchase and the right to eventually obtain a deed to the property if the delinquent taxes, along with any interest and penalties, are not paid by the property owner within a redemption period. The redemption period typically lasts for two to three years, but it can vary depending on the specific circumstances. If the property owner fails to redeem the property by paying the owed taxes, the certificate holder may petition the court for a tax deed, after which they can take ownership of the property. The foreclosure process for tax liens in Illinois involves court proceedings to ensure the validity of the lien and to provide a legal avenue for the sale of the property to satisfy the debt.