A contractual lien is a name for a category of liens that stem from contracts and do not depend on the common law or statutes for their existence. A contractual lien is essentially a contract that gives a security interest in property to one of the parties involved. One example would be a mortgage.
Some insist that a "contractual lien" should not be called a lien at all, because a "true" lien should arise without the consent of the property owner. Still, others argue that the concept of contractual liens adds value to discussions about the law.
[Last updated in July of 2022 by the Wex Definitions Team]