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 Minnesota, 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 initiate a tax forfeiture process, which is a form of foreclosure. After a redemption period, during which the homeowner can pay the back taxes plus interest and penalties to remove the lien, the property may be sold at a public auction. The process for enforcing property tax liens and conducting tax-forfeited land sales is governed by Minnesota Statutes, specifically Chapter 279 for tax delinquency and Chapter 280 for judicial proceedings related to tax delinquency. Federal tax liens for unpaid income taxes are governed by federal law and are filed by the Internal Revenue Service (IRS). These liens also attach to all of the taxpayer's property, including real estate, and can be enforced through a federal court process.