Signage or curb paint defective
Most Missouri cities enforce parking restrictions only where signs are posted at conforming intervals and curb paint is visible and not faded. A missing or obscured sign, faded red/yellow curb paint, or contradictory signage at the location is a clean dismissal ground.
Wrong vehicle code section on the citation
Every MO parking citation must cite a specific vehicle code, municipal code, or DMV ordinance section. If the cited section does not match the location's actual restriction (e.g. wrong street-cleaning day, wrong zone), the citation is defective on its face.
Meter malfunction or system outage
A Jefferson City citation issued while the meter was broken, the pay-by-phone app was down, or the kiosk would not accept payment is dismissable on the "machine malfunction" ground. Time-stamped evidence (screenshot of the error, photo of the meter) significantly strengthens the dismissal brief.
Statute-of-limitations or service defect
In most US states, a parking citation must be served on the vehicle (placed on the windshield or affixed to a visible point) at the time of the contravention. A citation mailed days later — without proper "notice of violation" being placed on the vehicle — typically fails the service requirement.