Facts
B. is the owner of a sole proprietorship in which his daughter A. (the plaintiff) is registered with sole signing authority. B. concluded a leasing contract with X. AG (the defendant), which was signed "jointly and severally" or as "joint and several debtors" by A. and B.'s wife C. After an accident with the leased vehicle, A. did not fulfill her payment obligation to the defendant, whereupon the defendant obtained provisional enforcement. A. then filed a declaratory action, which was upheld by the High Court.
The defendant appeals against this judgment, arguing that A.'s obligation was wrongly qualified as an invalid surety rather than as a cumulative assumption of debt.
Considerations
The Federal Supreme Court dismisses the appeal. It states that the surety is subject to special formal requirements by the legislator in order to protect the surety from incautious commitment. The cumulative assumption of debt, on the other hand, is valid without any formal requirements.
The decisive factor for the distinction is whether the obligated party has a recognizable own interest in the transaction that goes beyond a mere security interest. If there is no such…