Inheritance agreement: a notarial deed, not a letter between heirs

An inheritance agreement is a contract by which a person binds themselves to another about their estate. Article 512 of the Civil Code requires authentic form, before a notary, with the parties. A private writing or a will signed only by the future deceased is not such an agreement. It may institute an heir or contain a waiver. It is not revoked by a later will alone. The statute provides grounds for termination and, in principle, the parties' agreement. It must respect the reserve of heirs who did not consent.