What a lien waiver is
A mechanic's lien is a legal claim a contractor or sub can file against a property when they haven't been paid for work performed or materials delivered. The lien attaches to the property itself, which is why owners and their lenders care about lien waivers — an unpaid sub on your job can cloud the owner's title and trigger their loan covenants.
A lien waiver is a sub (or supplier, or contractor) signing a document that says, in effect, “I'm giving up my lien rights for this work, in exchange for getting paid for it.” That's why every well-run pay-app cycle collects waivers from every sub who billed against the period.
The two axes — conditional vs unconditional, partial vs final
Industry standard waivers split on two axes, giving four documents:
1. Conditional Partial
Used most often. Sub waives lien rights for work through this period conditional on actually receiving payment. Common pattern: sub signs the conditional partial when they submit their invoice; the waiver becomes effective when the GC's check clears.
Owner is happy because they have a waiver in hand at draw time. Sub is happy because the waiver only kicks in if they actually get paid. Use this on every monthly pay app.
2. Unconditional Partial
Sub waives lien rights for work through this period regardless of whether they get paid. Riskier for the sub — if the check bounces or the GC defaults, the sub has already given up their lien rights for that period and has only contractual claims left.
Used at draw time when the owner's lender requires it, but typically only after the sub has confirmed receipt of the prior period's payment. Common pattern: sub submits a conditional partial for the current period AND an unconditional partial for the prior period (now paid).
3. Conditional Final
Sub waives all lien rights for the entire project conditional on receiving final payment. Used when the sub is closing out and submitting their final invoice. The waiver is signed at submission; effective on payment receipt.
4. Unconditional Final
Sub waives all lien rights for the entire project regardless of whether they receive final payment. This is the document the owner wants in the closeout binder. Sub should only sign and deliver after final payment has cleared the bank.
The standard sequence on a pay-app cycle
- GC requests a draw from the owner. Owner's lender requires waivers from every billing sub.
- Each sub signs and submits a conditional partial for the current period with their invoice.
- For subs that billed last period, they also submit an unconditional partial for the prior period(the period they got paid for).
- GC packages all the waivers with the AIA G702/G703 and submits the draw.
- Owner pays the GC. GC pays the subs. The conditional partials become effective.
At closeout, the sequence is the same except with final waivers instead of partial. Conditional finals at submission; unconditional finals after payment clears.
State-specific notes
A number of states prescribe the lien-waiver form by statute, and where a statute prescribes a form, a document that doesn't substantially conform can be unenforceable — “substantially” gets read as “exactly.” The list is longer than most GCs think (Arizona and Michigan get left off a lot of these lists), a few states scope the requirement to residential work, and at least one prescribes a form while still permitting alternatives.
This is not legal advice.Don't work from a list you found online, including this one — the answer turns on your state, whether the job is public or private, and your contract date. Confirm your state's current requirement, or have a construction lawyer in your jurisdiction read the form, before you send a waiver you intend to rely on.
Common mistakes
- Signing the unconditional waiver before the check clears.Once you sign, you've given up your lien — you can't un-sign it because the wire failed.
- Sub forgets to specify the period.A waiver with no “through” date is an argument waiting to happen — the owner will read it as broadly as the language allows. Always specify the through-date or the pay-app number.
- Treating supplier waivers as optional.Suppliers (lumber yards, equipment rental, material suppliers) have lien rights too. Collect waivers from them as well — a supplier's lien clouds the owner's title exactly like a sub's, and the amount that makes filing worth their while is smaller than you'd guess.
- Missing waivers from second-tier subs.Your sub's sub also has lien rights. Owners on big-dollar jobs sometimes require waiver chains down two levels.
How neuroBLDR helps
When you mark a pay app as paid in neuroBLDR, conditional partial lien-waiver records can be created for subs with matching bills in that pay period — pre-filled with the sub, amount, period, and project. The sub can sign through its project-scoped magic-link portal, and the unsigned items remain visible to your team.
Conditional or unconditional, partial or final — neuroBLDR supports the four common waiver types, pre-filled with the sub, amount, period, and project, with portal signing and an audit record. Review the form with your counsel before relying on it.