Missouri’s lemon law, codified under § 407.560 et seq. (part of the Missouri Merchandising Practices Act), protects buyers of new vehicles and demo vehicles from defects that substantially impair use, value, or safety. If your vehicle has a serious defect that cannot be fixed after reasonable repair attempts, Missouri law entitles you to a full refund or replacement at no additional cost. The law also provides for attorney fee recovery if you prevail, making it practical to hire legal representation to pursue your claim.

This guide walks you through Missouri’s lemon law requirements, documentation needs, and the claim filing process.

Missouri Lemon Law: Key Facts

Aspect	Details
Statute	§ 407.560 et seq. (Merchandising Practices Act + Lemon Law)
Coverage	New vehicles + demo vehicles
Mileage/Time Limit	First 18 months or 18,000 miles
Repair Attempts Required	4 attempts OR 30 days out of service
Arbitration Required First?	Yes (if manufacturer certified)
Attorney Fees	Yes
Enforcement Agency	Missouri Attorney General’s Office

What Qualifies as a Lemon in Missouri

A vehicle qualifies as a lemon under Missouri law if:

It has a defect that substantially impairs its use, value, or safety
The defect is covered under the manufacturer’s warranty
The defect occurs within 18 months of purchase or before 18,000 miles (whichever comes first)
The defect cannot be repaired after a reasonable number of attempts
The defect is not caused by abuse or misuse

“Reasonable attempts” means:

4 or more repair attempts for the same defect, OR
The vehicle is out of service for 30 cumulative days for warranty repairs, OR
2 or more repair attempts for a defect that creates a safety hazard

Missouri protects both new vehicle buyers and demo car purchasers. The law applies to manufacturing defects, electrical failures, transmission problems, and persistent design flaws that cannot be corrected.

How to Document Your Lemon Claim

Build a strong case with comprehensive documentation:

Repair records: Obtain and keep all service invoices, work orders, and repair confirmations from the dealership
Warranty documentation: Maintain your purchase agreement, warranty booklet, and any supplemental warranties
Defect description: Document when the problem first appeared and what exactly goes wrong
Repair timeline: Record the date of each repair attempt, mileage, what was done, and whether the issue was resolved
Out-of-service tracking: Keep a log of all days the vehicle was at the dealer for repairs
Communication records: Save copies of all emails, letters, and texts to the dealer or manufacturer
Phone call logs: Document each phone call (date, time, person, summary of conversation)
Photos and videos: Capture the defect if possible (warning lights, mechanical failures, etc.)
Purchase documentation: Keep the bill of sale, title, and registration

How to File a Lemon Law Claim in Missouri

Step 1 — Send Written Notice to the Manufacturer

Send formal written notice to the manufacturer. Your notice must include:

Your full name, address, and contact information
Vehicle identification number (VIN), year, make, and model
Date of purchase and current mileage
Complete description of the defect
Dates and details of all repair attempts (with copies of service records)
Total days the vehicle has been out of service
Request for refund or replacement
Deadline for response (typically 10 business days)

Send the notice via certified mail with return receipt requested.

Step 2 — Attempt Manufacturer Arbitration (If Certified)

If the manufacturer has a certified arbitration program, Missouri law may require you to participate before filing suit. The manufacturer will:

Make one final repair attempt, or
Request binding arbitration

At arbitration:

Present evidence that the vehicle is a lemon
The manufacturer presents its defense
A neutral arbitrator decides whether to award refund, replacement, or repair
The decision is typically binding on the manufacturer (you may appeal to court if dissatisfied)

If the manufacturer is not certified for arbitration, you may skip this step and proceed directly to litigation.

Step 3 — File a Lawsuit

If arbitration fails or is not available:

File suit in Circuit Court for the county where you live or where the vehicle was purchased
You can recover the full purchase price, sales tax, registration fees, and attorney fees
Cases involving safety defects may qualify for enhanced damages

Real Situations in Missouri

Kansas City: A buyer purchased a 2024 Hyundai Elantra that developed a persistent electrical gremlins issue—dashboard lights flickering, radio cutting out, and power window failures. After 4 repair attempts over 8 weeks at the Hyundai dealer, the problems persisted. The buyer sent notice to Hyundai and pursued the manufacturer’s arbitration program. The arbitrator ruled in the buyer’s favor, awarding a full refund of the $26,500 purchase price.

St. Louis: A buyer bought a 2023 Toyota RAV4 with transmission issues manifesting within the first month and 2,000 miles. The vehicle spent 32 cumulative days at the dealer for transmission diagnosis and repair attempts within the first year. Using the “30 days out of service” rule, the buyer filed a lemon law notice. Toyota authorized a replacement vehicle of equal value rather than proceed to arbitration.

Springfield: A buyer purchased a 2024 Ford Escape that experienced a brake system warning 5 weeks after purchase. This safety defect triggered expedited lemon law protection. After one failed repair attempt, the buyer sent written notice. Ford offered a full refund to resolve the claim quickly.

Common Mistakes Missouri Lemon Law Buyers Make

Not participating in manufacturer arbitration when required: If the manufacturer has a certified program, failing to participate can complicate later litigation. Follow the arbitration process even if you believe you have a strong case.
Mixing repair attempts with different defects: While all days out of service count regardless of defect type, keep separate records for each distinct problem to clearly show when the 30-day threshold is reached.
Missing the 18-month deadline: Once you exceed 18 months or 18,000 miles, you lose lemon law protection. Act quickly if you suspect a defect.

This article is for informational purposes only and does not constitute legal advice. Last reviewed: March 2026.

Missouri Lemon Law: What Qualifies and How to Get a Refund or Replacement (2026)