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 New Jersey, a property tax lien is a legal claim against a property for unpaid property taxes. When property taxes are delinquent, the municipal government can place a lien on the property. If the taxes remain unpaid, the lien can lead to a tax sale, where the lien is sold to an investor. The investor can then charge the homeowner interest and eventually foreclose on the property if the debt is not paid. The process for tax sales and foreclosure due to tax liens is governed by New Jersey state statutes, specifically N.J.S.A. 54:5-1 et seq. The foreclosure process is judicial, meaning it must go through the court system, and the property owner is given the opportunity to pay the taxes owed, plus interest and costs, before losing the property. For federal tax liens, such as those for unpaid federal income taxes, the Internal Revenue Service (IRS) can place a lien on all of a taxpayer's property, including real estate, personal property, and financial assets. Federal tax liens are governed by federal law, and the IRS has its own process for enforcing them, which can also lead to the seizure and sale of the taxpayer's property to satisfy the tax debt.