A mistake is material if it is of such gravity that the contracting party would have refrained from concluding the contract had they not fallen into it. A mistake is considered material in particular: 1. If it occurs in a desired attribute of the thing that is essential in the consideration of the contracting parties, or shall be considered as such, given the surrounding circumstances of the contract and requirements of good faith. 2. If the mistake occurs in the identity of the contracting party or in an attribute thereof, and such identity or attribute was the principal reason for entering into the contract.
Interpretation and application must be checked against the official text and current version.