Guide to acquiring French citizenship – comprehensive legal, practical and procedural overview

I. Context and historical foundations

French nationality law is the outcome of two centuries of tension between jus sanguinis (bloodline) and jus soli (birth on national soil). The revolutionary legislation of 1790 favoured almost unlimited jus soli, only for the Napoleonic Civil Code of 1804 to swing back to an ancestry model (art. 18 CC). A new compromise emerged in the nationality act of 22 July 1889: children born in France to a parent who was likewise born in France would be French from birth — the celebrated double jus soli, now codified in article 19-3. Through the twentieth century, automatic acquisition broadened while voluntary naturalisation hardened: income checks appeared in the 1930s, language tests in the 1980s, and enhanced security screenings after 2015.

Integral to today’s system are

(i) the Civil Code articles 16-1 to 33-6,

(ii) Decree n° 2021-1907, which digitises all filings,

(iii) circular NOR INTK1802006J, defining accepted evidence of language, integration and residence,

and (iv) a robust body of Conseil-d’État judgments.

An applicant therefore navigates both black-letter rules and dense administrative practice.

II. Legal sources and competent authorities

Statutes and decrees – Articles 17–33-6 CC outline the modes of acquisition, loss and recovery. Decree n° 2021-1907 (30 Dec 2021) obliges prefectures to process files via the ANEF-NATION portal, sets electronic-document standards (PDF ≤ 10 MB, Latin filenames) and imposes a four-month deadline for initial completeness checks (art. 9 dec.).

Circulars and instructions – Circular INTK1802006J (26 Oct 2022) lists acceptable language diplomas (DELF, DALF, TCF, TEF), explains how residence continuity is calculated (absences ≤ 6 months consecutive or ≤ 10 months total in five years), and provides a values-interview grid covering secularism, gender equality and fundamental freedoms. Internal notes (e.g. INTB2100820C, 5 Apr 2023) refine economic thresholds and security-screening time-frames.

Decision-making chain – The local préfecture receives the dossier, interviews the applicant and issues a preliminary opinion. The Service de la nationalité française (SDANF) in Paris performs legal review. The DGSI and OFPRA run security and asylum checks. The prime minister signs the naturalisation decree; its publication in the Journal officiel perfects acquisition (art. 21-15 CC).

Judicial oversight lies with the tribunal administratif de Nantes (first instance), the cour administrative d’appel de Nantes (appeal) and ultimately the Conseil d’État (cassation).

III. Automatic acquisition by birth or descent

1. Child of a French parent – Under article 18 § 1 CC, a child is French from birth when either parent holds French nationality. Place of birth is irrelevant; the rule applies worldwide.

2. Double jus soli – Article 19-3 grants French nationality at birth to a child born in France if one parent was also born in France, even if the parent is foreign.

3. Conditional jus soli – Article 21-7 confers nationality automatically at age 18 on a child born in France to foreign parents, provided residence in France totals at least five calendar years since age 11. Parents may accelerate via declaration at age 13 or 16 (art. 21-11).

4. Adoption – A plenary adoption by a French national (art. 18-1) renders the adoptee French immediately. A simple adoption does not.

Each mode is origin-based and produces an irrevocable status save for fraud (art. 27-2).

IV. Naturalisation by decree

1. Residence requirement (art. 21-17) – Five years of lawful, continuous, habitual residence. Lawful: valid carte de séjour or carte de résident throughout. Continuous: absences must not exceed six consecutive months or ten cumulative months in the quinquennium (circular table 2). Habitual: France must be the centre of economic and family life (CE, 5 Jul 2019, n° 428 907). Exceptions: two-year residence for holders of a French master’s degree or for “exceptional integration” (art. 21-18); three years for active military service under arms.

2. Language and values (art. 21-24) – The applicant demonstrates French at CEFR level B1. Approved certificates: DELF B1, DALF, TEF Intégration, TCF Intégration. Exemptions: five-year French-language schooling (CE, 27 Feb 2019, n° 417 273) or graduation from a French-language university. During the entretien d’assimilation, prefecture officers employ a standard 15-question bank on republican symbols, secularism and equal rights.

3. Moral character (art. 21-27) – Serious offences (felonies, repeated violence, tax fraud > 80 000 €) block naturalisation for ten years after rehabilitation. Minor misdemeanours trigger discretionary refusals if they reveal “insufficient moral integrity”. The Conseil d’État (CE, 30 Dec 2022, “M. P.”) requires a proportionality test.

4. Economic integration – Not expressly codified, yet prefectures apply a SMIC-based threshold. Workers submit the last twelve payslips plus three annual avis d’imposition. Self-employed provide three certified balance sheets, VAT returns and a chartered-accountant liquidity letter.

5. Digital dossier – Applicants create an ANEF account, upload identity papers, birth certificates with apostille, civil-status translations, residence permits, tax notices, payslips, language certificates and police records (French Bulletin n° 2 plus foreign certificate ≤ 3 months old). File-names use ASCII only; the portal rejects diacritics.

6. Prefectural steps – Within four months the prefecture either (a) issues a récépissé de complétude or (b) requests missing documents. After validation, the applicant attends the interview. A positive prefectural opinion moves the dossier to SDANF.

7. Central processing – SDANF sends security requests to DGSI (counter-intelligence) and OFPRA (asylum overlaps). If both are favourable, SDANF drafts a decree, the prime minister signs and publication occurs within two weeks. Average timeline: Paris 14–18 months; Lille 12–14 months; rural prefectures 9–12 months.

8. Appeals – A refusal letter (art. 21-25 CC) triggers a 2-month window for (i) a recours gracieux to the interior minister or (ii) direct judicial challenge before the tribunal administratif de Nantes (art. R.421-1 CJA). The judge applies full legality review; annulment obliges the ministry to reassess.

V. Citizenship through marriage

Article 21-2 creates a declaration-based acquisition after four years of marriage (three if the couple lived together in France continuously). Residency of the French spouse abroad prolongs the clock. Proof: joint income-tax returns, lease, mortgage, shared utilities and social-security registration. Criminal records as for naturalisation. The prefecture investigates vie commune; sham marriages or separation during examination nullify the process (CE, 19 Feb 2020, n° 427 403). Language level B1 remains obligatory.

VI. Reintegration of former French nationals

Articles 24-1 to 24-3 allow former citizens to regain nationality without residence-duration requirements, provided they demonstrate “ties of culture, family or profession” and meet language and character tests. Typical cases: descendants of Alsatian families who opted for German nationality before 1919, expatriates who lost nationality by acquiring US citizenship before French law permitted dual status, or Swiss residents whose parents renounced French citizenship after 1945.

VII. Special naturalisation categories

• Military service (art. 21-14-1) — Foreign soldiers wounded in operations receive immediate citizenship; Legionnaires may apply after three years of honourable service.

• Exceptional merit (art. 21-19) — Nobel prizes, Olympic medals, COVID vaccine pioneers, global tech founders; the minister must document “exceptional services rendered to France’s influence”.

• Children in state care (art. 21-12) — Foreign minors taken into French guardianship for ≥ 5 years since age 11 may acquire citizenship by declaration.

VIII. Revocation, renunciation and security measures

• Fraudulent acquisition — Article 27-2 allows revocation within ten years where nationality was obtained by fraud, lie or forged document.

• Offences against the state — Article 25 permits deprivation for crimes such as treason or terrorism, but only if the person holds another nationality, respecting the 1961 convention on statelessness. Deprivation is ordered by decree after Council-of-State advice.

• Voluntary renunciation — Article 23-6 authorises renunciation if the person has another nationality and the minister deems renunciation “in the public interest”.

IX. Procedural rights and judicial review

Refusal may rest on articles 21-24 (insufficient assimilation), 21-27 (public order) or 21-25-1 (incomplete residence). The tribunal administratif verifies legality, factual accuracy and proportionality. If annulled, the ministry must issue a new decision within six months (art. L.911-2 CJA). Appeals progress to the Nantes appellate court and then the Conseil d’État on points of law (art. R.832-1 CJA).

X. Digital pitfalls and practical advice

Scans should be 200 dpi colour, merged per document, with an index page. Photos taken with smartphones often exceed 10 MB; compress to 300 ppi. Apostilles must appear in the same PDF as the underlying civil-status extract. Use English-or-French filenames: BirthCertificate.pdf, not Geburtsurkunde Müller.pdf. Back-up every upload because ANEF auto-deletes after 30 minutes of inactivity.

Keep an absence log: plane tickets, boarding passes, EU exit-entry stamps. Exceeding the authorised gap leads to automatic rejection unless exceptional grounds (force majeure) are proved.

XI. Illustrative cases

An Argentinian PhD in physics completes a two-year post-doc at the École normale supérieure, meets the shortened residence period and secures citizenship in eleven months.A Nigerian nurse passes DELF B1, but irregular cash-in-hand work reduces declared income; refusal for economic insufficiency follows. She regularises contributions, files an appeal, and wins after the tribunal holds that nursing labour shortages constitute exceptional integration.A Korean artist marries a French curator, lives three years in Lyon, but long stretches abroad for exhibitions break the vie commune. Application rejected; the Conseil d’État confirms, highlighting objective separation.

XII. Future reforms

The draft immigration bill 2024 originally called for a language increase to B2; the Senate set it aside. Decree projects for 2026 aim to integrate biometric validation directly in the ANEF portal and to pilot AI for fraud detection. A proposed “climate talent pass”, offering expedited nationality to innovators in decarbonisation, circulates in white-paper form but lacks parliamentary sponsorship.

Conclusion

French nationality remains both attainable and demanding. The state offers multiple automatic paths for the second generation and structured voluntary routes for well-integrated adults, but scrutinises language, morality and economic self-sufficiency. Applicants worldwide should assemble a chronological, meticulously scanned dossier, respect file-size limits, maintain residency continuity and prepare for a rigorous civic interview. Where refusals occur, administrative courts provide meaningful review. With careful preparation, the journey culminates in the Journal officiel — and full civic rights in a founding member of the European Union.

For tailored support at every stage, contact us via https://www.rous-avocat.fr/contact