My grandfather has just passed away. He has left my aunt, my brother and me as heirs. In his will, he indicated that the available portion would go to his daughter. The notary tells me that my aunt is entitled to 2/3 of the inheritance. Is this true?

Yes. In accordance with Article 734 of the French Civil Code, in the absence of a surviving spouse, children and their descendants constitute the first order of heirs. Article 913-1 of the Civil Code specifies that all descendants are included under the term 'children,' “even though they are to be counted only for the child whose place they hold in the succession of the disposing person”.

In other words, as your grandfather had two children, his share of the available portion is 1/3 of his estate (Article 913 of the French Civil Code). Your aunt receives the available portion (1/3) thanks to the will and her share of the reserve (1/3). You and your brother share your father's share of the inheritance reserve (1/3).