No. The law does not recognize the surviving civil partner as a legal heir, unlike the surviving spouse. Therefore, if you want your partner to be your (sole) heir, you will need to make a will to that effect. This can be drafted by a notary (authentic form) or by your own hand (holographic).
Good to know : the civil partner, like the surviving spouse, is exempt from inheritance tax (Article 790-0 bis of the General Tax Code).
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