A vendor stopped delivering. A client stopped paying. A partner walked away from a signed deal. When someone breaks a contract with your Missouri business, you want to know three things fast: can you prove it, what can you recover, and how long do you have. This guide answers all three under Missouri law — and it serves the other side too, because the same rules tell you how to respond if someone accuses you of breaching.

One caution up front: contract cases turn on their documents and facts. This guide gives you the framework, not a prediction about your dispute.

Missouri law requires you to prove four things

A breach-of-contract claim in Missouri has four elements. You must show all of them:

A valid contract existed. Offer, acceptance, and consideration — each side gave or promised something of value.
You performed. You did what the contract required of you, or you stood ready and able to perform when the other side made performance pointless.
The other side breached. They failed to do something the contract required, did it late, or did it defectively.
The breach caused you damages. You lost money because of the breach, and you can show roughly how much.

Claims die on the first element more often than you might expect. A vague email exchange, a quote someone never accepted, a "handshake deal" nobody can reconstruct — these fail at element one. Before you count damages, make sure you can prove the deal itself: the signed document, the accepted purchase order, the invoices the other side paid under the agreement.

Not every breach lets you walk away from your own duties. Missouri distinguishes a material breach — one that defeats the essential purpose of the deal — from a minor one. If the breach is material, you may stop performing and sue for the whole contract. If it is minor, you still must perform, and your remedy is damages for the shortfall. Call a small defect "material" at your own risk: if a court disagrees, your refusal to perform becomes the breach.

Some contracts must be in writing — or they fail entirely

Oral contracts are generally enforceable in Missouri. The problem is proof, not validity. But Missouri's statute of frauds, § 432.010, RSMo, takes whole categories of agreements off the table unless a writing signed by the party you want to hold responsible exists. The main categories:

A promise to answer for someone else's debt (a guaranty)
An agreement that cannot be performed within one year from the date it was made
A contract for the sale of land or any interest in it, including a lease longer than one year
An executor's promise to pay estate debts from personal funds
An agreement made in consideration of marriage

The writing need not be a formal contract. A signed memorandum covering the essential terms can satisfy the statute. But a missing signature or a missing essential term — an unidentified property, an unstated price — can sink the deal.

Missouri courts recognize narrow escape hatches. Part performance can save an oral land contract when the buyer's actions make sense only if the deal existed. Full performance works too: if both sides completely performed an oral agreement, the statute of frauds no longer bars suit. And under the "main purpose" rule, a guaranty need not be written when the person promising to pay another's debt did so chiefly to serve his own interest. Do not plan around these exceptions. Get the writing.

Deadlines kill more contract claims than defenses do

Missouri gives most contract plaintiffs five years. Under § 516.120, RSMo, suits on contracts — express or implied, written or oral — must be filed within five years, with narrow exceptions. Many business owners assume a signed contract buys ten years. It usually does not. The ten-year period in § 516.110, RSMo covers a smaller class: writings for the payment of money or property, such as promissory notes, plus a few other listed actions. Missouri courts have put ordinary contract suits — including suits on written contracts like leases — under the five-year clock. In Bangert v. Boise Cascade Corp., for instance, a suit over liquidated damages in a lease covenant was treated as an ordinary contract action governed by § 516.120, not the ten-year statute.

Two more clocks matter:

Goods: four years. If the contract is for the sale of goods, Missouri's version of the Uniform Commercial Code, § 400.2-725, RSMo, sets four years from the breach. The clock runs when the breach occurs even if you do not yet know about it. The parties may agree to shorten the period to as little as one year, but they cannot lengthen it.
Accrual: when the clock starts. A contract claim generally accrues when the breach happens and the resulting damage can be ascertained — not when you get around to calling a lawyer. Fraud claims run on a different track: the five-year period starts when the defrauded party discovers the facts, subject to an outer ten-year limit, as Anderson v. Dyer explains in construing § 516.120.

Limited tolling doctrines exist for concealment and similar circumstances, but they are exceptions you should never count on. Diarize the earliest plausible accrual date and treat it as the deadline.

What you can recover

Missouri's basic measure is expectation damages: the money that puts you where full performance would have put you. If a supplier failed to deliver and you paid $8,000 more to buy the same goods elsewhere, that $8,000 difference — plus certain downstream losses — is the starting point. Several rules shape the number:

Consequential damages must be foreseeable. You can recover losses beyond the contract price — lost sales, idled crews, penalties you owed others — only if those losses were within the parties' reasonable contemplation when they made the deal, and you can tie them to the breach. A loss the breaching party had no reason to foresee stays on your books.

Damages must be reasonably certain. Missouri courts reject speculation. Lost profits are recoverable, but you must prove them with reasonable certainty — typically through business records, history, and comparable performance. A brand-new venture with no track record faces a steep climb. Win liability without proof of amount and you may collect only nominal damages.

Liquidated damages clauses work — if they are not penalties. When the parties fixed damages in advance, Missouri enforces the clause if real damages were hard to estimate at signing and the fixed amount reasonably forecasts the loss. A figure designed to punish rather than compensate is an unenforceable penalty.

Interest adds up. When no contract rate applies, § 408.020, RSMo, allows creditors nine percent per year on money due under written contracts, and on accounts once due and demanded. On a stale six-figure receivable, prejudgment interest alone can be worth thousands — but it is generally unavailable where damages rest on unliquidated lost profits.

Attorney fees follow the American rule. Each side pays its own lawyers unless the contract says otherwise or a statute authorizes fees. A well-drafted fee-shifting clause is one of the most valuable sentences in any business contract; its absence changes settlement math on both sides.

You must mitigate. Missouri will not fund avoidable losses. After a breach, you must take reasonable steps to limit the damage — cover the goods, re-rent the space, replace the worker. You recover the costs of reasonable mitigation, but not losses you could have ducked.

The defenses that decide these cases

If you are on the receiving end of a demand — or testing the strength of your own claim — these are the defenses that matter most:

No enforceable contract. Missing essential terms, lack of consideration, or a statute-of-frauds problem ends the case early.
The statute of limitations. Five years for most contracts, four for goods, ten for the narrow class of money writings. A late claim is a dead claim.
No material breach. The complained-of shortfall was minor, so it did not justify the other side's refusal to perform.
Failure of consideration. The plaintiff never delivered what it promised, so nothing was owed in return.
Waiver and estoppel. The plaintiff accepted late or defective performance without objection for months; it cannot suddenly declare a default on the same conduct.
Impossibility and impracticability. Performance became objectively impossible — not merely more expensive — through no fault of the breaching party.
Failure to mitigate. The plaintiff let losses pile up that reasonable effort would have avoided.
Speculative damages. Liability may be clear, but the claimed amount is guesswork.

One boundary deserves special mention. When the only harm is the disappointed economic expectation from the contract itself — the product does not work as promised, the service fell short — Missouri law generally keeps the claim in contract. You usually cannot recast a broken deal as a negligence case to chase tort damages. Lawyers call this the economic loss doctrine, and it quietly disposes of many creative complaints.

What to do before you sue

Lawsuits are expensive and slow. Most contract disputes settle, and the side that prepares early settles better. Take these steps first:

Pull the documents. The contract, every amendment, the statements of work, invoices, payment records, and the emails and texts around the deal. Store them somewhere safe and stop auto-deletion.
Read the contract's fine print. Notice-and-cure clauses may require written notice and a waiting period before you can declare default — skip one and your lawsuit may fail on a technicality. Look for arbitration clauses, forum-selection clauses, and fee-shifting terms. They control where and how you fight.
Send a real demand letter. State the contract, the breach, the dollar amount, and a deadline. A clear demand often produces payment, starts interest running on accounts under § 408.020, and later shows the court you acted reasonably.
Build the damages number. Assemble the proof now: invoices, replacement costs, profit history. If you cannot quantify the loss with reasonable certainty today, a jury will not do it for you later.
Check the calendar. Identify the breach date and work out the limitations period with margin to spare. Do not sit on a claim.
Weigh the business case. Add up likely recovery, attorney fees, months of management attention, and the chance of collecting a judgment. Sometimes the right move is a negotiated discount, a structured payment plan, or walking away — decided with clear eyes rather than pride.

If a lawsuit comes

Contract cases in Missouri are filed in the circuit court of the county with proper venue — often where the defendant resides or where the breach occurred. Smaller disputes may fit within associate circuit procedures, which move faster and cost less. After filing, both sides exchange documents and take depositions in discovery; most cases settle during or after that phase, once each side has seen the other's evidence. A bench or jury trial decides the rest.

Expect the defense to attack your four elements, your damages math, and your mitigation. Expect the case to take months, not weeks. And expect the outcome to turn on documents written long before anyone thought about court — which is why the steps above matter more than anything that happens in the courtroom.

The bottom line

Missouri breach-of-contract law rewards the prepared. Prove the deal, your performance, the breach, and a reasonably certain number. Respect the five-year clock — four for goods — and the writing requirements. Document your mitigation. And before anyone files anything, read the contract you actually signed: its notice, cure, arbitration, and fee clauses often decide the dispute before a judge ever sees it.

Frequently asked questions

Can I sue on an oral contract in Missouri?

Yes, in most cases. Oral contracts are enforceable unless they fall within the statute of frauds — guaranties, agreements that cannot be performed within a year, land sales, and leases over one year under § 432.010, RSMo. Outside those categories, your real challenge is proving the terms, not establishing validity.

How long do I have to file a breach-of-contract lawsuit in Missouri?

Five years for most contracts under § 516.120, RSMo, counted from when the breach occurred and the damage became ascertainable. Sale-of-goods contracts carry four years under the UCC, and a narrow class of writings for the payment of money gets ten. When in doubt, assume the shortest period and act early.

Do I have to accept defective performance and just eat the loss?

No, but measure your response. A material breach lets you stop performing and sue for the whole contract. A minor breach obligates you to keep performing while you pursue damages for the shortfall. Treating a minor breach as material can turn you into the breaching party.

Talk to a Missouri litigation attorney

If a broken contract is costing your business money — or someone claims you broke one — get advice before deadlines or missteps narrow your options. Ott Law Firm handles contract disputes and complex litigation from St. Louis. Call (314) 710-2740 or contact us online to discuss your situation. You can also learn more about our litigation practice and related work in real estate disputes and employment matters.

This article is for informational purposes only and is not legal advice. Contract outcomes depend on specific facts and documents, and statutes change. Consult a Missouri attorney about your situation before acting or letting a deadline pass.

Breach of Contract Claims