Lien Waiver
A document a contractor, subcontractor, or supplier signs giving up their right to file a [[concept-mechanics-lien|mechanic's lien]] against a property for a specific amount of work, usually exchanged for a payment, and often required before that payment is released at all.
Why it matters
An owner paying for work wants proof that the money won't be followed by a lien anyway, whether from the party they paid directly or from someone further down the chain who never got their share. Lien waivers are what turn a payment into a clean, final transaction instead of an open risk.
On a real project
Before releasing a subcontractor's monthly payment, a general contractor requires a signed conditional waiver, valid only once the check actually clears, along with waivers from that subcontractor's own material suppliers, so nobody down the chain can still file a lien for the same work.
Who this matters most to
A Contracts Administrator collects and tracks lien waivers as a routine part of processing every payment, since a missing waiver can hold up funding on some projects. A Project Manager relies on a complete set of final waivers at closeout to confirm the project is actually free of lien risk before releasing the last payment.
Where this goes wrong
A general contractor accepts an unconditional lien waiver from a subcontractor before the subcontractor's payment check has actually cleared. The check bounces, but the subcontractor has already legally waived their lien rights for that amount, leaving them without their strongest tool to recover the unpaid money, a mistake a conditional waiver would have prevented.