A British worker who has paid National Insurance in the United Kingdom and social-security contributions in France does not necessarily lose a French pension right because the two records are kept by different administrations. After Brexit, the relevant question is which coordination instrument covers the worker’s cross-border situation, which periods are recognised by each country and whether the institutions have exchanged the evidence needed to calculate the pension. The arrangement is not a transfer of British contributions into a French account and it is not an automatic conversion of one UK qualifying year into four French quarters.

The practical problem is familiar: a French relevé de carrière (career record) shows only French employment, the UK National Insurance record shows only British years, and a pension forecast appears to omit the other country’s periods. That can affect the right to claim, the French taux plein (full-rate percentage), the date at which a reduction disappears and the amount paid by each country. It is different from the taxation of a UK pension. For that separate issue, see our guide to where UK pensions are taxed for a person living in France.

This article explains the post-Brexit framework, the evidence to gather and the route to follow when a French pension fund has not included relevant UK periods. It covers a person who owns the pension right personally, whether living in France or the UK. It does not deal with incorporating a company, buying property or transferring a pension into a QROPS.

I. Can UK insurance periods still count towards a French pension after Brexit?

A. Which Brexit agreement protects French and UK periods, and what does “totalisation” mean?

The first mistake is to treat Brexit as a single switch that ended every cross-border pension right on 31 December 2020. The legal analysis has two layers. A person in a protected situation at the end of the transition period may rely on the social-security provisions of the Withdrawal Agreement. A person whose relevant mobility falls after that date may fall under the social-security protocol to the EU–UK Trade and Cooperation Agreement, commonly abbreviated as the TCA. The exact instrument depends on the person’s residence, work and insurance history, not simply on British nationality.

The French Centre for European and International Social Security Liaison (CLEISS) explains the practical effect in its Brexit FAQ. It states that the Withdrawal Agreement preserves the coordination rules for relevant pre-2021 activity and that the TCA permits French and UK activity periods to be taken into account reciprocally. The official answer uses the phrase permet la prise en compte de vos périodes d’activité. The CLEISS Brexit FAQ should be read alongside the facts of the individual career, because it distinguishes activity before the end of the transition period, continued UK activity and situations beginning after 1 January 2021.

The TCA is not only a trade document. Its social-security protocol coordinates, among other branches, old-age and survivors’ pensions. The official EU summary records the coordination of old-age and survivors’ pensions and identifies the Protocol on Social Security Coordination. In a retirement case, the relevant rules can allow periods completed under one country’s legislation to help satisfy a minimum period under the other country’s legislation, subject to the scope and conditions of the instrument.

“Totalisation” is the French term for adding recognised insurance periods for the purpose of testing entitlement. It does not mean that France pays a pension for British wages or that the UK pays a pension for French wages. Each competent institution applies its own legislation and normally pays the share attributable to the periods under that legislation. CLEISS describes the mechanism as a calculation in which each country may first examine the whole coordinated career and then apply a proportional share. The CLEISS explanation of international retirement calculations distinguishes totalisation from proratisation, the proportional allocation of the resulting amount.

A useful example is a person with fourteen years of National Insurance in England, eight years of employment in France and a French pension age approaching. The UK record may be enough to open a UK State Pension, while the French record may need the UK periods to avoid an incomplete insurance duration for the French rate. If the agreement applies, the French institution can request confirmation of the UK periods through the liaison process. It will not copy the UK salary into the French average annual salary. The UK will calculate its own benefit under UK rules, while France calculates its own benefit under French rules.

The UK’s own guidance gives the same logic in reverse. It says that a person with fewer than ten UK qualifying years may still qualify where contributions were made in a country covered by the applicable coordination rules, and that foreign periods may be added when the claim is made. The current GOV.UK guidance on the new State Pension when a person has lived or worked abroad says: Time spent making contributions in these countries can be added to the qualifying years. It also makes clear that the amount paid is not automatically the same as the amount that would have resulted from a wholly UK career.

The date of the work matters. A British national who was working in France before the end of the transition period, or who was in a continuing protected cross-border situation, should preserve documents showing that status. A person who moved to France for the first time in 2024 should not simply quote the Withdrawal Agreement without examining the TCA rules. Conversely, a recent move does not mean that the worker has no coordination protection. The correct question is whether the relevant activity and the claim fall within an instrument that coordinates old-age benefits.

The legal effect is also different from a private pension transfer. A defined-benefit workplace pension, a personal pension, a SIPP or a QROPS is governed by pension-scheme and tax rules. The coordination of statutory insurance periods concerns the State Pension or French basic retirement regimes, not the capital value of a private pot. A British resident in France can therefore have three separate files: the UK National Insurance and State Pension file, the French basic pension file and the private pension tax file.

The distinction is especially important after the UK’s 2026 change to voluntary contributions for periods abroad. HM Revenue & Customs says that from 6 April 2026 the measure abolishes voluntary Class 2 National Insurance contributions for periods working or living outside the UK and changes the requirements for voluntary Class 3 contributions. The official GOV.UK policy paper records that change. It does not, by itself, erase a completed French insurance period or answer whether France must take it into account under a coordination agreement.

A person should therefore make four preliminary checks before arguing about missing quarters:

• identify every country in which statutory old-age insurance was paid or credited;
• separate employment, self-employment, unemployment credits and residence periods, because the agreement may treat them differently;
• record the date on which the person lived or worked in France and the UK, especially 31 December 2020 and 1 January 2021; and
• decide whether the dispute concerns entitlement, the rate, the amount, the date of payment or only a private pension.

That classification avoids a common dead end. A French pension fund may correctly tell a claimant that UK periods do not appear on the online French record. The absence of a foreign period from the screen does not necessarily mean that the period will be ignored in the final international calculation. The CLEISS guidance on international retirement calculations explains the coordination mechanism and the difference between a domestic record and the later international calculation.

The principle has also been applied in litigation involving a British worker. In Cour de cassation, Second Civil Division, 7 November 2019, no. 18-18.344, the Court considered a career in France, the United Kingdom and Monaco. It held that a British national could claim the relevant totalisation of UK and French periods, while the different France–Monaco calculation had to be compared separately. The judgment refers to la totalisation des périodes d’assurance acquises au Royaume-Uni et en France. This was a pre-Brexit decision applying the then European framework, but it is a precise illustration of the legal distinction between adding periods for entitlement and merging pension payments.

The decision also gives a practical warning: the best calculation may need to be compared with more than one legal route. If a career includes France, the UK and a third country, the institutions must identify which instruments can be combined and whether the periods overlap. A claimant should not assume that every period in every country can be stacked without limit. Ask the French fund to state which agreement it applied, which periods it accepted, which it excluded and whether it performed both the national and coordinated calculations.

B. What do French pension rules do with the foreign periods, and why does the UK record still matter?

French law starts with the French pension itself. Article L. 351-1 of the Social Security Code states that old-age insurance guarantees a pension when the insured person claims it at the statutory age, and that the amount depends on the annual salary, the rate and the insurance duration. The opening sentence is L’assurance vieillesse garantit une pension de retraite. The article does not create a right to copy UK earnings into France. The international instrument supplies the coordination mechanism; French law supplies the domestic calculation.

The French durée d’assurance means the insurance duration used in the pension calculation. A French quarter is not a simple calendar quarter. French domestic rules validate quarters by reference to earnings, credited periods and statutory limits. UK records use qualifying years and National Insurance credits. Coordination therefore works through the legal categories recognised by the agreement. It is unsafe to multiply a UK year by four and insert the result into the French record without an institutional calculation.

Article L. 351-2 of the Social Security Code states that insurance periods are retained only if a minimum level of contributions was paid, while allowing proof by documents or concordant presumptions where force majeure or manifest impossibility makes direct proof difficult. The statutory phrase is Les périodes d’assurance ne peuvent être retenues. For a UK period, this does not authorise the French fund to demand a French payslip. It does mean that the claimant must establish that the period was a recognised period of statutory UK insurance, not merely an informal job or an unverified estimate.

The corresponding UK question is whether the year is a qualifying year on the National Insurance record and whether it is available for coordination. The UK’s official State Pension guide explains that qualifying years may be built from employment, National Insurance credits, self-employment and voluntary contributions. It gives the current statutory context in Your State Pension explained. A payslip alone may not show the final HMRC record. A claimant should obtain the official National Insurance record and forecast, then reconcile them with employment documents.

The amount of the French pension is not determined only by the total number of coordinated periods. The French fund must examine the domestic calculation and the coordinated calculation. In the domestic calculation, only the periods and earnings recognised under French rules are used. In the coordinated calculation, the foreign periods may help determine the rate or entitlement, while the French institution pays a proportion linked to French periods. The claimant should request both figures in writing and ask the fund to show the number of French quarters used, the foreign periods used and the denominator adopted.

This is the point at which a missing UK period can cause a financial loss even if no French contribution is missing. Suppose the French record contains 112 quarters, the French law requires a longer duration for the full rate, and the UK record contains ten recognised years. If the UK periods are ignored, the French pension may be reduced because the rate is lower or because the coordinated right is not opened. If the periods are recognised, France still does not pay the UK share, but the French calculation may avoid the reduction or establish a right that would otherwise be denied.

The French information right is useful before the pension claim. Article L. 161-17 of the Social Security Code provides for information on statutory retirement rights and an individual statement of the person’s situation. The text gives every person the right to obtain un relevé de la situation individuelle. The online statement is not a final international pension decision, but it creates a baseline. Download the French record, the UK National Insurance record and any international pension forecast before asking for a correction.

The French administration may exchange data with other schemes. Article L. 161-17-1-1 concerns the electronic communication of information needed to determine pension rights and their calculation. That does not remove the claimant’s duty to cooperate. Electronic liaison can fail because the name differs, the National Insurance number is missing, the French social-security number is wrong, the employer reported a different date or the request was filed with the wrong fund.

The record must also distinguish “validated” from “contributed” periods. A French career record can show periods that count for the rate but are not treated as contributed periods for every advantage. The Court of cassation highlighted this distinction in Second Civil Division, 4 May 2016, no. 15-17.061. The case concerned an inaccurate reading of a career record and a claim for a contributory minimum. The judgment describes the issue as periods “validated” free of contributions versus periods actually contributed. It is a reminder that the words on a forecast must be read carefully: “total periods”, “contributed periods”, “assimilated periods” and “periods used for the rate” are not interchangeable.

A more recent decision makes the proof point even clearer. In Second Civil Division, 4 June 2026, no. 23-23.554, the Court partially quashed a decision that had accepted a supplementary-pension record as sufficient proof of payment of basic pension contributions. The Court said that the document was impropre à caractériser … le paiement ou le précompte des cotisations for the relevant period. For a British worker, an employer’s letter or a private pension statement can support the file, but the central evidence should be the official UK insurance record or a formal confirmation from the competent UK institution.

The result is not that a claimant must produce one perfect document before making a claim. It is that evidence must be directed to the legal question. A tax return can prove that a person lived in the UK, but it may not prove that National Insurance was paid. A P60 or payslip can prove employment, but it may not show the final qualifying year. A State Pension forecast can show the UK record, but it may not identify how the period should be transmitted to France. Use a bundle and explain the role of every document.

A British worker should also keep the tax analysis separate. A UK State Pension paid to France may be taxable under the France–UK tax treaty and French domestic rules. A French pension paid to the UK may have a different treaty treatment. Those rules do not determine whether UK insurance periods count towards a French pension. The same person can win the social-security coordination argument and still need to correct a tax return, or lose a treaty tax argument while retaining the pension entitlement.

The practical answer to “can my UK periods count?” is therefore yes, potentially, but only through the applicable coordination instrument and a verified record. A missing foreign period on the French online account is a reason to prepare the international file, not a reason to assume that the period has been rejected. A written calculation from the pension fund is the point at which a true refusal can be identified.

II. How can a British worker correct the record and challenge a refusal?

A. Which documents should be sent, and how should the international pension request be framed?

Start with a two-column reconciliation rather than a general complaint. In the first column list every French period by year, employer and regime. In the second list every UK period by tax year, employer or self-employment status, National Insurance class or credit and the evidence available. Add a third column for gaps and overlaps. The objective is to show precisely which period is missing and what result it could affect.

For the United Kingdom, request or download:

• the National Insurance record showing qualifying years, credits, gaps and the status of each year;
• the State Pension forecast and the date on which the forecast was generated;
• letters from HMRC or the Department for Work and Pensions about disputed years or voluntary contributions;
• P60s, payslips, employment contracts and employer payroll records for years missing from the official record;
• self-employment accounts, Class 2 or Class 4 evidence and tax returns where the activity was self-employed;
• benefit or National Insurance credit decisions for unemployment, sickness, caring or parental periods; and
• any earlier international pension correspondence, including forms or references showing that France was contacted.

For France, collect the relevé de carrière, the relevé de situation individuelle, the French social-security number, French payslips and employer certificates. Download the relevant notices from the retirement account. The public French retirement services allow a person to view the record year by year and request a correction through the career-update function. The fact that foreign activity is absent from the French view should be recorded, but not treated as conclusive proof of refusal; the CLEISS Brexit FAQ confirms that periods can still be taken into account under the applicable coordination rules.

Write a short chronology. State when you worked in the UK, when you worked in France, where you lived during each period, which institution received the contributions and when you first noticed the missing period. Identify the applicable Brexit situation: protected activity before 31 December 2020, a continuing situation covered by the Withdrawal Agreement or activity falling under the TCA from 1 January 2021. If there are multiple moves, include the dates rather than describing the career as simply “pre-Brexit” or “post-Brexit”.

Use a clear request in French even if the supporting documents are in English. For example: “Je demande la prise en compte, pour l’ouverture et le calcul de mes droits à l’assurance vieillesse, des périodes d’assurance accomplies au Royaume-Uni du [date] au [date], dans le cadre de l’instrument de coordination applicable après le retrait du Royaume-Uni. Je vous remercie de transmettre la demande à l’institution britannique compétente et de me communiquer le calcul national et le calcul coordonné.” In English, that asks for the UK insurance periods to be taken into account for entitlement and calculation, the international liaison request to be sent and both calculations to be disclosed.

Send the request to the competent French pension fund, not to a general tax office. If you live in France, the regional pension fund for your place of residence will usually be the first contact. If you live in the UK and have French periods, the route may depend on the last French affiliation, the place of residence and whether a retirement claim has already been made. The CLEISS international-retirement guidance explains the coordination of periods and why the French institution must identify the applicable instrument before calculating the pension.

Do not wait until the day before the chosen pension start date. International correspondence can take months, particularly where the UK record has a name variation, a National Insurance number mismatch or an employer that no longer exists. The French guidance advises making contact around five months before the selected start date. That is a planning recommendation, not a guarantee that the claim will be calculated by that date. A person close to retirement should request the record earlier and keep proof of every submission.

Ask for an acknowledgement that states what has been received. A portal screenshot showing “document sent” is useful, but a complete file should also contain the PDF, the date, the recipient and the reference number. If a French fund says that it cannot request UK information because no UK period is visible, reply with the official National Insurance record and ask the fund to open an international coordination request. If the UK says that it cannot assess a French period because France has not confirmed it, ask the French fund for the exact information it sent and the date of the transmission.

Check identity details across every document. British surnames may change after marriage; French administration may omit a middle name; a person may have both a French social-security number and an old temporary number; and UK records may contain a different spelling of a first name. Attach the passport identity page, marriage or civil-partnership certificate where relevant, proof of address and any document linking the numbers. Redact bank details that are not needed, but do not remove the identifiers required to locate the record.

Translate the evidence intelligently. The pension institution may accept an English UK government record without a certified translation, but it can ask for clarification or French translation of an employer document. Do not translate a technical term into a misleading French equivalent. Keep the original “qualifying year”, “National Insurance credit”, “Class 3 contribution” or “contracted-out period” next to a short explanation. If the dispute turns on an official decision, provide the full decision and a faithful translation of the operative part, not an informal summary.

Before sending, prepare a one-page calculation note. It should say:

• French periods accepted in the current record;
• UK periods shown on the official National Insurance record;
• periods overlapping in the same months or years;
• the French age and insurance duration relevant to the proposed retirement date;
• the result requested: opening of the right, full rate, amount, start date or correction; and
• the documents that prove each disputed period.

Overlaps deserve particular attention. A person may have been employed in France while a UK employer treated them as temporarily posted, or may have paid voluntary UK contributions while working under French legislation. The coordination rules do not allow the claimant to choose two countries simply because the combined result is higher. Ask which country’s legislation applied to the work and whether the period is contributory, credited, equivalent or excluded. The UK and French institutions, not the claimant’s spreadsheet alone, must make the final classification.

It is also worth checking whether the French dispute is about the basic pension or an additional scheme. French retraite complémentaire means an additional occupational pension, usually administered under a different set of rules from the basic régime général. The UK National Insurance record generally speaks to the UK State Pension, not to a French supplementary-pension points account. A letter sent to the wrong scheme can produce a technically correct answer that does not resolve the missing-period problem.

The UK side should be pursued in parallel where its own record is wrong. If HMRC has omitted a qualifying year, correct that record first or ask for a written explanation. If the issue is a voluntary contribution decision after the 6 April 2026 rule change, identify the class, the period abroad and the applicable eligibility test. Do not ask the French fund to certify a UK year that HMRC itself has not recognised. The French institution can coordinate the period; it cannot rewrite the UK National Insurance record.

B. What can a British worker do after a French refusal or an incomplete calculation?

Demand a written decision. A telephone answer from a call centre may explain the current screen but is not a safe basis for a time-limit calculation. Ask the French fund to state whether it refuses to recognise the period, refuses to request confirmation from the UK, considers the period outside the applicable agreement, or accepts the period for the rate but not for the amount. Those are different decisions and require different evidence.

If the decision comes from a French social-security organisation and concerns the pension record or calculation, the usual first administrative route is the commission de recours amiable, or CRA. This is an internal amicable-review commission, not a court. Article R. 142-1 of the Social Security Code provides that claims against decisions of the social-security organisations are submitted to a CRA and states: Cette commission doit être saisie dans le délai de deux mois from notification of the contested decision. Keep the envelope, email header or portal date because the starting point matters.

The appeal should identify the decision, the period, the legal instrument, the requested correction and the supporting documents. Attach the National Insurance record, not just a screenshot of a forecast. Quote the exact French record line that is wrong or missing. Explain whether you request a new international liaison inquiry, a corrected French calculation, a comparison between the domestic and coordinated calculations or payment of arrears. A general statement that “Brexit has cost me my pension” is less effective than a table showing the missing year and the result it changes.

The CRA is not a substitute for the underlying evidence. If the first request omitted the UK document, submit it with the CRA claim and identify it by date and page. If the French fund says the document was not received, include proof of delivery. If a translation is requested, send the translation and restate the date on which the two-month period should be calculated. Do not assume that a later upload automatically restarts every deadline; ask the fund to confirm the procedural position in writing.

A silence can have procedural consequences. The current rules provide that, in the ordinary CRA procedure, a failure to notify the applicant of the decision within the prescribed period may be treated as a rejection. The current Légifrance provisions on the prior appeal procedure record that the period runs from receipt of the claim, subject to the effect of later documents, and that the claimant may treat the application as rejected when no decision is notified within the relevant period. Keep a calendar and obtain legal advice before issuing a court claim because the applicable route can vary with the fund and the nature of the dispute.

After the prior appeal, a pension dispute may be brought before the competent judicial court dealing with social-security matters, subject to the procedural conditions and time limits in the notification. The court will examine the decision, the evidence and the law. It will not usually invent a missing UK insurance record. The file should therefore contain the official UK response, the French exchange history and a precise calculation. If the UK institution has not responded, ask the French court to order or facilitate the production of the relevant administrative evidence where procedurally available, but continue the UK follow-up.

There is a useful distinction between a refusal based on law and a refusal based on proof. A legal refusal says, for example, that the person is outside the personal or material scope of the TCA. The response should address residence, work and the relevant dates. A proof refusal says that the fund cannot establish the period. The response should address the National Insurance record, employer evidence, credits and the institutional request. Mixing the two arguments makes the appeal longer but less clear.

Courts scrutinise the actual content of the career record. In the 2016 decision no. 15-17.061, the Court of cassation quashed part of a decision and sent the matter back because the calculation did not sufficiently analyse the document used to identify the number of contributed quarters. In a cross-border claim, the same discipline matters: a decision should not say merely “the foreign periods are not shown”. It should identify the document, explain the category of period and show the calculation. The judgment’s procedural lesson is more useful than a generic assertion that a forecast is binding.

The 2026 decision no. 23-23.554 also shows why the proof should be tied to the statutory basic scheme. The Court held that a supplementary-pension career statement, without more, did not establish payment or withholding of basic pension contributions for the disputed period. The practical equivalent for a British worker is to use the official National Insurance record as the primary document and private pension statements only as corroboration. If the official record is incomplete, the claimant must first obtain an HMRC or DWP decision, payroll archive, employer certificate or other legally probative material.

Use the 2019 British-worker decision carefully. It confirms that the legal system can require a comparison of coordinated calculations, but it arose under the pre-Brexit European rules and involved a third-country convention with Monaco. The current post-Brexit claim must identify the Withdrawal Agreement or TCA basis. The decision is still valuable because it rejects the idea that a British worker’s French and UK periods can simply be disregarded when the relevant coordination rules require them to be examined.

Do not miss a UK remedy. If the French fund has sent a request to the UK and the UK record is disputed, contact the International Pension Centre or the relevant HMRC/DWP service with the French reference. Ask for the decision in a form that can be sent to France. If the UK refuses to correct a National Insurance record, use the review or appeal route identified in the UK decision. A French CRA cannot correct an English administrative record, and a UK appeal cannot order the French fund to apply Article L. 351-1 in a particular way.

Calculate the financial consequence before litigating. The missing period may change the French rate but not the French average salary; it may open a pension right but still result in a small French pro-rata amount; or it may change only the date at which a reduction disappears. It may also affect a minimum pension, a survivor’s benefit or a tax-related residence file. Request a written comparison with and without the disputed UK periods. A claim for arrears should identify the date from which the pension should have been recalculated and any applicable limitation issue.

Keep a separate evidence index for any future hearing. Number the documents, state the issuing body, date and relevant page, and explain what each proves. A clear index might label the UK record “U1”, the French career record “F1”, the employment contract “U2”, the French payslips “F2”, the international correspondence “I1” and the pension calculation “C1”. In a remote cross-border case, this is more reliable than sending a folder of unlabelled scans to a French administration.

The following checklist is suitable for a first review:

1. download the current French career record and UK National Insurance record;
2. mark the missing period by month and year;
3. identify the Brexit agreement and the person’s residence and work dates;
4. separate State Pension, French basic pension and private pension issues;
5. obtain official evidence of the UK period and supporting payroll or credit documents;
6. ask the French fund for the international liaison request and the two calculations;
7. obtain a written decision if the period is refused or ignored;
8. file the CRA claim within the applicable two-month period where Article R. 142-1 applies;
9. calendar the response and court deadlines; and
10. pursue any separate HMRC or DWP correction in parallel.

A British worker who has moved to France should also check practical contact details. The French fund must have the current address, email, bank details and a reliable way to receive a decision. A move between France and the UK can change which institution receives the claim or which country is responsible for transmitting it. Notify changes through the official account and by written message when a time limit is running. Keep the French and English reference numbers together.

The strongest case is narrow. It does not ask the French fund to award a British pension, convert UK salary into French salary or treat every year abroad as four French quarters. It asks the institution to apply the correct coordination instrument, obtain confirmation of a defined UK insurance period, distinguish the national and coordinated calculations and issue a reasoned decision. That is the request a CRA or court can test.

Conclusion

UK National Insurance periods can still help a British worker establish or calculate French retirement rights after Brexit when the person’s situation falls within the Withdrawal Agreement or the social-security protocol to the EU–UK Trade and Cooperation Agreement. The result is coordination, not a merger: France and the UK each apply their own pension rules and pay the share connected with their own legislation.

If the French record does not display UK periods, obtain the official National Insurance record, the French relevé de carrière, the relevant residence and work chronology and the documents proving each disputed year. Ask the competent French fund to transmit the international request and to disclose the domestic and coordinated calculations. If the fund refuses or remains incomplete, obtain a written decision and use the CRA within the applicable two-month period, while pursuing any HMRC or DWP correction separately.

The practical value of the claim may be the opening of a French pension, a higher French rate, a corrected retirement date or a better calculation of a survivor’s right. It cannot be assessed from the number of years alone. The agreement, the legal category of each period, the evidence and the exact calculation all matter.

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