Mo. R. Sm. Clm. Div. Cir. Ct. 143.03
As amended through October 1, 2024
At any time within ten days after service of process and before the date of trial, the defendant may assert a counterclaim that does not arise out of the same transaction or occurrence as the plaintiff's claim by filing the counterclaim with the clerk of the small claims division in substantially the form approved in Rule 152. A copy of the counterclaim shall be mailed or delivered to the plaintiff.
Mo. R. Sm. Clm. Div. Cir. Ct. 143.03