A contractor's lien (often known as a mechanic's lien, or a construction lien) is a claim made by contractors or subcontractors who have performed work on a property, and have not yet been paid. A supplier of materials delivered to the job may also file a mechanic's lien. In some states, professionals such as architects, engineers, and surveyors may also be entitled to file a lien for services rendered on a home improvement project.

Lean Priority and Lien Waivers

The priority of liens on a construction project does not depend upon the time of completion of the particular job, but rather everything relates back to the first visible commencement of the work. This stipulation means the final work (such as painting) is equal in priority to the initial work of laying a cement foundation. Therefore, during the entire work of construction, the owner must obtain lien releases or waivers of lien from each subcontractor and material supplier. Without these waivers or releases, the real estate is subject to liens of all the subcontractors, even if the general contractor (though paid in full) fails to pay the subcontractors.

Lien Notification

In some states, contractors and subcontractors must notify the property owner prior to filing a lien, but in other states such liens can be filed without any notification to the owner. Lien claimants who are contractors or subcontractors are protected under this legal doctrine because all their materials and labor are "buried" in the real estate, having become part of it. Unlike mortgage liens, however, the liens of these claimants cannot force a foreclosure.