Is sister’s British will valid in France?

It is not ideal estate planning to rely on an English format will alone if you are resident in France (though people sometimes have a French will limited to French assets and an English one for English assets). As it will not respect the format of a French will and will need translating it can cause additional complications.

Differences between an English-format will and French ones include the fact that one can draw up an English will without a lawyer’s help, either typed or handwritten, and it has signatures added to it by two witnesses.

On the other hand a French will made without a notaire, un testament olographe, is handwritten and unwitnessed.

None of this however means that a will in an English format (and written in English) is invalid in France nor is it invalidated by not having been lodged with a notaire for safekeeping and for its details to be placed on a national register. The latter is an advisable step to ensure a will is found but not doing it does not invalidate a will.

Notaire Pierre Lemée, editor of the journal Conseils des Notaires, said France recognises the validity of a will made by a British person in the British format. However it will need translating by a sworn translator (traducteur assermenté).

The notaire can apply French inheritance law to this British-format will if applicable (or one of the British legal systems if such a choice was expressed).

You should seek advice from a French notaire.