A legal claim on a property that requires the payment of an associated debt when the property is sold. A mortgage is a type of lien but liens may also be placed against a property for unpaid income taxes, property taxes or other debts incurred by the property owner.
Example: Bill hires a general contractor to make some improvements to a property he’s recently purchased. The contractor places a mechanic’s lien against the property as surety that he’ll be paid for his services.