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 Oregon, 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 can 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 may initiate foreclosure proceedings to recover the owed taxes. This process involves a court determining the validity of the lien and the appropriate satisfaction of the debt. The property may then be sold at a public auction to satisfy the lien. For federal income 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 federal tax lien process is governed by federal law, while property tax liens for state and local taxes are governed by Oregon state statutes.