Wisconsin Statutes Joint Obligations (Ch. 113) § 113.11. Release of joint debtor; effect

(1) If any creditor to whom persons are jointly indebted, either upon contract or the judgment of a court of record, shall release any of them such release shall operate as a satisfaction or discharge of such joint debt to the amount of the proportion which the person so released ought in equity, as between the person and the other joint debtors, to pay; and the balance of such joint debt shall remain in force as to joint debtors not released and may be enforced against them. If the amount paid by a debtor to procure the release shall exceed the proportion of such joint debt which the debtor, as between the debtor and co-debtors ought to pay then such joint debt shall thereby be satisfied to the extent of the sum so paid. If the person released is only a surety the person's release shall operate as payment of such joint debt to the extent of the money paid by the person and no further.

(2) This section does not permit the discharge of a principal debtor without also discharging the principal debtor's sureties.