When having repair or remodeling work done on your home, Missouri law allows general contractors to put a lien on your property (known as a mechanic's lien) if you fail to pay.
A mechanic's lien can only be placed by the general contractor. Missouri law does not allow subcontractors (such as plumbers) to put liens on property, even if the general contractor fails to pay them.
You want to avoid signing a Consent of Owner statement. This revokes that legal protection and allows any contractor — general or sub — to put a lien on your property if they don't get paid.
State law is different for new home construction. In this case, any contractor can put a lien on your property if they are not paid. That means you could pay the general contractor, but if he fails to pay the subcontractor, the sub can file for a lien against you. To avoid this, insist that your general contractor provide lien waivers from all subcontractors.