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 Iowa, a property tax lien is a legal claim against a property for unpaid property taxes. When property taxes are not paid, the county treasurer may place a lien on the property. This lien has priority over other liens or claims on the property, meaning it must be paid first if the property is sold. If the taxes remain unpaid, the county can initiate a tax sale process, where the property is sold at a public auction to satisfy the tax debt. The original homeowner may have a redemption period, typically one to two years, to pay the back taxes plus interest and fees to retain ownership of the property. If the redemption period expires without payment, the tax sale certificate holder may petition for a tax deed to obtain ownership of the property. For federal tax liens, the Internal Revenue Service (IRS) can place a lien on all of a taxpayer's property, including real estate, for unpaid federal taxes. The IRS may also force the sale of the property to collect the debt. Both state and federal tax liens are matters of public record, and the processes for enforcing these liens involve legal proceedings to ensure the validity and satisfaction of the lien.