Sue for Unpaid Invoice in Missouri Small Claims Court

When an Invoice Goes Unpaid Long Enough

You finished the work, sent the invoice, followed up twice, and heard nothing. Maybe the client ghosted you entirely. Maybe they acknowledged the debt but keep pushing the date back. Either way, Missouri's small claims division lets you recover up to $5,000 without hiring a lawyer — and for most sole traders and freelancers, that covers the bill.

Small claims cases in Missouri are heard in the Associate Circuit Court under RSMo § 482.305. You file one form (Petition SC40), pay a filing fee between $20.50 and $45 depending on your county, and receive the hearing date on the summons. Ask the clerk about the current scheduling timeline in your county.

Check the Statute of Limitations First

Missouri gives you different windows depending on whether the agreement was written or verbal:

• Written contract or signed invoice agreement: 10 years under RSMo § 516.110
• Oral agreement or handshake deal: 5 years under RSMo § 516.120

The clock starts on the date payment was due, not the date you did the work. If you invoiced net-30 and the due date was March 15, 2022, your five-year window runs from that date.

If you're inside the window, you can file. If the invoice is close to the deadline, file sooner rather than later — the petition must be filed before the statute expires, not just the demand letter.

Send a Demand Letter Before Filing

A demand letter isn't legally required for breach-of-contract claims in Missouri, but it serves two purposes. First, it often gets the debtor to pay without a court appearance. Second, a written demand can support a request for 9% prejudgment interest on a liquidated debt under RSMo § 408.020; the court decides whether interest is warranted.

Your demand letter should include:

• The debtor's full legal name and mailing address
• A description of the work you performed and the original agreement
• The exact amount owed, including any late fees the contract specified
• A payment deadline (10 to 14 business days is standard)
• A clear statement that you'll file in small claims court if they don't pay

Send it by certified mail with return receipt requested. Keep the green card — it's evidence.

Gathering Your Evidence

Judges in Missouri small claims hearings decide cases based on the documents and testimony you present. For an unpaid invoice claim, bring three copies of everything (one for the judge, one for the defendant, one for you):

• The original contract or written agreement — even an email chain confirming the scope and price counts
• The invoice itself — with the amount, date issued, and payment terms
• Proof of delivery — completion photos, signed delivery receipts, email confirmations that the work was accepted
• The demand letter and certified mail receipt — showing you gave notice before filing
• A communication log — texts, emails, or voicemails where the debtor acknowledged the debt or promised payment

If the agreement was oral, your testimony about the terms is admissible. But any written confirmation — even a text saying "I'll pay you next Friday" — strengthens your case substantially.

Filing the Petition

You'll file OSCA Form SC40 at the Associate Circuit Clerk's office in a county where the debtor resides; where you reside and the debtor can be found; or where the facts giving rise to the claim occurred, under RSMo § 482.330. On the form you'll state the amount owed (up to $5,000), describe the facts briefly, and sign a declaration that you haven't filed more than 12 other claims in Missouri small claims courts this calendar year.

Filing fees vary by county — $20.50 in St. Louis County, $27.50 in Jackson County, $35.50 in Greene County. Certified mail service is about $10; sheriff service is $46 in Jackson County, $49 in St. Charles County (including $9 mileage, effective March 1, 2026), and $55 in Greene County.

You can file in person, by mail, or electronically through Missouri's eFiling system at courts.mo.gov. Track your case afterward on Case.net.

What Happens at the Hearing

Missouri small claims hearings are informal. There's no jury and rules of evidence are relaxed. The judge will ask you to explain your claim, then let the defendant respond.

Present your evidence in order: the agreement, the invoice, proof you did the work, the demand letter, and the communication log. Be factual and concise. Don't editorialize about the debtor's character — stick to what they owe and why.

If the defendant has been duly served and doesn't appear, you still must present a prima facie case; the judge may enter a default judgment, which can include court costs, under RSMo § 482.355. If the defendant appears and disputes the claim, the judge decides based on the evidence.

After the Judgment

If you win, the defendant has 10 days to file an Application for Trial de Novo under RSMo § 482.365, which moves the case to a new hearing in the Associate Circuit Court. If no appeal is filed, your judgment is final.

The court doesn't collect the money for you. If the defendant doesn't pay voluntarily, you may need to pursue wage garnishment or other collection methods — the sibling guide on Missouri small claims judgment collection covers that process.

The Organized Approach Saves Time

Most freelancers and small business owners lose small claims cases not because the debt isn't real, but because they show up without organized documentation. Our Missouri small claims filing guide walks you through every step from the demand letter to the hearing, with fillable worksheets for tracking deadlines, organizing evidence, and identifying the correct defendant — so you don't waste a courthouse trip on a technicality.

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