A lien gives the creditor certain rights over the property of the debtor until the debt is paid. A mechanic's lien, sometimes called a materialman's lien, is used by contractors and subcontractors who perform construction work on real property. This may relate to labor and materials provided for constructing a new building or for a project for an addition or repair work. A lien document is filed in the public land records by the contractor, so that anyone doing a title search can find it. The property owner will find it difficult, or impossible, to sell or refinance the property unless the debt is paid and the lien released by the contractor. A lien release is a document that is filed in the public land records as the official notice that the lien is removed. Once payment has been received, a contractor has a duty to remove any lien that was filed against the property. Failure to do so allows the property owner to file a lawsuit against the contractor to compel the lien's removal. It should be noted that a lien release is not the same as a lien waiver. While a release removes an existing lien, a waiver is an agreement that prohibits a contractor or supplier from placing a lien on the property. It's important to understand that liens are governed by state law, which varies from one state to another. Some states don't permit lien waivers at all. State law may also dictate the information that needs to be included in a release, and may even have suggested or required release forms. How and when liens may be placed and released may also be governed by the terms of the contract, to the extent permitted by state law.