Are joint wills and inheritance contracts permissible?

Swiss inheritance law only permits inheritance contracts, which in practice are often used by spouses. The formal requirements of public wills apply to the drafting of inheritance contracts. Inheritance contracts can be cancelled in writing by mutual agreement, Article 513 para. 1 of the Swiss Civil Code. There is a possibility of unilateral cancellation if there was an error on the part of one party, a reason for disinheritance arises or the other party defaults on the promised payment.