Wis. Stat. § 113.03: Recoveries credited, limitation.

The amount or value of any consideration received by the obligee from one or more of several obligors, or from one or more of joint, or of joint and several obligors, in whole or in partial satisfaction of their obligations, shall be credited to the extent of the amount received on the obligations of all co-obligors to whom the obligor or obligors giving the consideration did not stand in the relation of a surety.