Contractor not paid in Missouri? Here's every lever, in order.

By Ty McDuffey, J.D. · Built at Lake of the Ozarks job sites

You have three levers, and the strongest one expires: a mechanic's lien against the property itself (six months from your last day of work — no grace period), Missouri's prompt-payment statutes that add interest to late checks, and the plain contract claim. The order you pull them in decides whether you're negotiating or begging.

Lever one: the mechanic's lien — the deadline that decides everything

Missouri lets the people who improved a property claim against the property itself under RSMo Chapter 429. The mechanics: your lien statement must be filed within six months of your last day furnishing labor or materials (§429.080); subcontractors and suppliers must first serve a ten-day notice of intent (§429.100); and once filed, the enforcement suit is due within six months of the filing (§429.170). Owner-occupied residential work carries extra consent-and-notice rules for subs. Run your exact dates on the Lien Clock right now — the six months is jurisdictional, and trivial warranty touch-ups do not restart it.

Why it works: owners and GCs who comfortably ignore invoices cannot ignore a cloud on title. A lien blocks refinances, complicates sales, and — on a project with a construction lender — makes you everyone's problem. Most lien matters settle in the lien's shadow without a suit ever being filed. And in a successful enforcement action, attorney fees can be recoverable — the leverage compounds.

Lever two: the prompt-payment statutes — interest on every late dollar

Missouri backstops construction payment timing by statute. On public projects, §34.057 requires owners to pay primes within thirty days of a proper invoice and primes to pay subs within fifteen days of receiving payment — with 1.5% per month interest on late amounts. On private projects, §431.180 requires payment according to the contract's terms and gives courts the power to award interest and attorney fees against a party that fails to pay per the contract. These claims stack with the lien — the lien secures the debt; prompt-pay makes delay itself expensive.

Lever three: the contract claim — and the paper that wins it

Underneath everything is the breach-of-contract suit: you performed, they didn't pay. What decides these cases is almost never the law — it's the file. Signed contract or the chain of emails that formed one, change orders in writing, delivery tickets, daily logs, photos, and the invoice trail. The demand letter that precedes the suit hits hardest when it arrives with the lien already filed and the interest already accruing: at that point you're not asking to be paid, you're offering a discount on the alternative.

The order of operations when a check goes missing

1. Lock your last-day date and run it through the calculator — everything else is scheduled backward from that deadline.
2. Send the required notice (the ten-day notice of intent for subs and suppliers) — early, not at the wire.
3. Assemble the file — contract, change orders, tickets, photos, invoices — while memories are fresh.
4. Demand in writing with a date certain, citing the lien deadline and the prompt-pay interest.
5. File the lien statement well inside the window if the check doesn't land — a "just and true account," accurately itemized, because sloppy statements get liens thrown out on paperwork alone.
6. Calendar the enforcement deadline the day you file — six months, and the lien lapses.

What smart operators fix before the next job

Every payment fight is cheaper to prevent at contract time: draw schedules with dates instead of vibes, change orders that don't start work until signed, a file habit that records first and last days on site, and a standing rule that the six-month date gets calendared the day a job goes sideways — not the month the check is officially late. Contract drafting built for how Lake jobs actually run is exactly the kind of flat-fee work this practice is being built around.

Educational content only, current as of July 13, 2026. Deadlines and notice duties vary by role and project type; verify against the current text of RSMo Chapter 429, §431.180, and §34.057. Not legal advice; no attorney-client relationship. The choice of a lawyer is an important decision and should not be based solely upon advertisements.