A Mechanic’s Lien Affidavit is a document used by contractors, suppliers, and any person that is not getting paid for the labor, services or materials delivered to a construction project. A mechanic’s lien, protects claimants by asserting rights against the actual real property (real estate) for the unpaid work or services performed on that specific property. Depending on where you are located, a Mechanic’s Lien Affidavit can also be referred as “Project Lien”, “Construction Lien” and even “Contractors Lien”.