French citizenship from the UK: descent, marriage and naturalisation
The consulate's nationality page sets out three routes, and they work very differently from the UK. The child of a French parent needs the first one, nationality from birth, and the task is to prove it.
French from birth: by descent
You are French by filiation if at least one parent was French on the day you were born, whether you were born in France or abroad and whether or not your parents were married, as long as the link with that parent was legally established while you were a minor.
A second case is "double droit du sol": born in France to a parent who was also born there.
The document that proves it is the certificat de nationalité française. The page is clear that consulates have no role in it: you send the request by post to the court of your place of birth in France or, if you were born and live abroad, to the Paris judicial court.
Service-Public.fr adds that someone living abroad who applied by post may be called in by the consulate.
| Route | Where it is handled | Fee |
|---|---|---|
| Descent (proof by CNF) | a French court, by post | none charged by the consulate |
| Marriage (declaration) | the consulate's nationality service | £213.21 (€255) |
| Naturalisation from abroad | the consulate's nationality service, by exception | £213.21 (€255) |
Acquiring it: marriage or naturalisation
A foreign spouse of a French national can make a declaration by marriage after four years of marriage, or five in some cases, with French at B2 level since 1 January 2026: the details are in French citizenship by marriage. The fee is £213.21 (€255) on the consulate's fee table.
Naturalisation normally requires five years' residence in France. Living abroad, you can apply only by exception, notably after five years working for the French state or a body whose activity serves French interests. Since 1 January 2026 a civic exam is also required.
- The form from Service-Public.fr, completed
- Full copies of the civil status documents, in their original language
- The other documents the form’s notice lists for your case
- The right court: place of birth in France, or Paris if born and living abroad
The London consulate also holds a welcome ceremony for new French citizens, about once a month, where the declaration is handed over.
Do not book the consulate for a CNF: the page says consulates cannot prepare or forward it; the court decides.Official sources:
Last checked against uk.diplomatie.gouv.fr and the sources linked above on 10 November 2026.
frenchconsulates.co.uk is an unofficial, independent guide to the French consular network in the UK.
No application can be made here. Where official pages contradict each other we say so; the consulate confirms what applies to you.