Certificate of French nationality (CNF): proof, documents, and where to apply
Understand what a CNF proves, the current Cerfa endpoint, required records, jurisdiction, receipt-based period, and refusal safeguards.
What is a CNF?
A certificat de nationalité française, or CNF, is formal proof of existing French nationality. It does not grant nationality. It identifies the facts, records, and legal provisions supporting the status.
Do not confuse it with:
- a transcription, which records a foreign civil-status event in French registers
- a passport or national identity card, which is an identity product
- a registered declaration or published decree, which can be an acquisition instrument
- naturalization, which is a separate prospective process
Read the family-chain guide before choosing this procedure.
Is a CNF always required?
No. It may be requested when nationality is in doubt, a person born abroad needs formal proof, older documents do not explain the basis, or another authority asks for it. An old passport, French birth act, SCEC transcription, or consular registration may help without replacing a CNF when formal proof is required.
Which form and records apply?
Use the live central Cerfa 16237 endpoint. Do not rely on a saved form filename.
The file is individual. The route-specific checklist commonly calls for:
- identity, address evidence, and a recent identity photograph
- original full civil-status copies in the original language
- original translations in the accepted form
- parentage records through the claimed French source
- the transmitting person's nationality basis, such as a CNF, judgment, registered declaration, or published decree
- apostille, legalization, or an exemption where required for that country, document, treaty, and receiving authority
A family tree explains the claimed sequence. It does not prove it. See documents, records, and archives and foreign-document formalities.
Where do you apply?
Current jurisdiction depends on residence and birthplace:
- If you live in France, use the nationality-competent judicial court for your domicile.
- If you live abroad and were born in France, use the competent court for your birthplace.
- If you live abroad and were born abroad, use the Tribunal judiciaire de Paris, service de la nationalité française.
Check the live official page before filing. Do not copy an old consular PDF or mailing address.
When does the official period start?
It starts when the court issues the récépissé, the receipt confirming a complete file. The current period is six months from that receipt. It may be extended at most twice, each time for six months. Gathering records before the receipt is outside that period.
The court registry may request more evidence and set a response date. Preserve every notice and delivery record.
What happens after silence or refusal?
Silence at the end of the applicable period is treated as refusal. A contentious challenge is due within six months after notified or implied refusal, and a lawyer is mandatory. A separate court action seeking a nationality judgment is not the same procedure, although counsel is also mandatory.
A prior refusal, implied refusal, or active six-month issue needs immediate manual legal review. Do not wait while trying to rebuild the file. Article 30-3 facts also need separate review. See the 50-year rule guide.
What should you do next?
Confirm the jurisdiction and live form. Then make a gap list showing what proves each family link and each parent's French status at the next birth. Correct material conflicts before paying for final formalities.
A French court or competent authority decides status. ByLineage is private and may match a case with an independent specialist.
Sources checked: 27 August 2026. Recheck the form, authority, channel, period, and appeal instructions on filing day.