Facts
[A. AG] , a joint-stock company domiciled in [U.] , whose purpose is the leasing of vehicles to third parties, particularly on the basis of leasing transactions, and all related business, filed a claim against [B.] , the proprietor of the sole proprietorship "[D.] " registered in the commercial register and domiciled in [W.] , for payment of CHF 41,125.00 plus interest. The basis of the claim was a declaration of solidarity signed by [B.] in connection with a leasing contract between [A. AG] and [C. AG] .
The Commercial Court of the Canton of Aargau dismissed the claim, as it qualified the declaration of solidarity as a formally defective surety and not as a valid joinder of debt. [A. AG] then filed a civil law appeal with the Federal Supreme Court.
Considerations
The Federal Supreme Court set aside the decision of the lower instance and remanded the case to the lower instance for supplementation of the findings of fact and a new decision. It concluded that the lower instance had wrongly interpreted the declaration of solidarity as a surety and not as a joinder of debt.
The Federal Supreme Court stated that the respondent [B.] , as a member of the Board of Directors of [C. AG] , was to be qualified as commercially experienced within the meaning of the case law of the Federal Supreme Court. Therefore, he had to accept the clear wording of the declaration of solidarity, which expressly referred to a joinder of debt and an independent debt obligation.…