For a British pensioner living in France, a deduction labelled CSG or CRDS on a French tax assessment can look like an unavoidable consequence of Brexit. It is not always. The answer depends on the legal category of the pension, the country whose compulsory health-insurance system covers you, the date and basis of the assessment, and the body that actually collected the amount. A UK-issued S1 can be decisive evidence, but it is not a universal tax exemption and it must be connected to the correct period and to your real social-security position.

This article addresses the person who receives a UK State Pension or another UK retirement pension while being tax resident in France and using an S1, the portable document that records entitlement to healthcare at the expense of the competent state. It explains when a refund claim may be justified, which amounts must be separated, how to build the evidence, and what to do if the first request is rejected. It does not treat the purchase of French property or the creation of a company. Those matters require a different legal analysis.

The practical conclusion is simple: do not claim every social levy merely because you hold an S1. First prove which scheme covered your healthcare during each disputed year and identify whether the charge concerns a pension, property income, a capital gain, or another payment. Then send the claim to the correct collector before the applicable time limit expires.

I. Can an S1 exempt a British pensioner from CSG and CRDS in France?

A. What is the legal test for a UK pension paid to a French tax resident?

CSG means contribution sociale généralisée, the French general social contribution. CRDS means contribution pour le remboursement de la dette sociale, the social debt repayment contribution. They are not the same as French income tax. They are social contributions, even though some foreign-source amounts are collected through the French tax system. This difference matters when deciding both the legal basis of the charge and the route for a refund.

The starting point is Article L. 136-1 of the French Social Security Code. The provision states, in the official wording, “Il est institué une contribution sociale sur les revenus d’activité et de remplacement”. It then limits the persons covered by the provision: a person must be tax domiciled in France and be dependent, in some capacity, on a compulsory French health-insurance scheme. The current text is available in Article L. 136-1 of the Code de la sécurité sociale.

A retirement pension is a “replacement income” for this purpose. Article L. 136-1-2 describes the contribution as applying to sums intended to compensate the loss of employment income and then lists exceptions and special rules for retirement and invalidity pensions. Its opening sentence is: “La contribution prévue à l’article L. 136-1 est due sur toute somme destinée à compenser la perte de revenu d’activité”. The relevant text is Article L. 136-1-2 of the Code de la sécurité sociale. The point for a British pensioner is not simply that the payment comes from the UK. The point is whether the French legal condition concerning compulsory French health insurance is satisfied for the period in question.

Where the pension is chargeable, Article L. 136-8 sets the ordinary CSG rate for retirement and invalidity pensions. The current provision says: “Sont assujetties à la contribution sociale au taux de 8,3 % les pensions de retraite, et les pensions d’invalidité”. The same article also provides reduced rates linked to the household’s revenu fiscal de référence (RFR), meaning the reference taxable income used by the French tax administration. The rate provision must be read in its version applicable to the year assessed; it is reproduced in Article L. 136-8 of the Code de la sécurité sociale.

CRDS has a separate statutory source. Article 14 of Ordonnance n° 96-50 du 24 janvier 1996 relative au remboursement de la dette sociale establishes the contribution on the categories of income covered by that ordinance. The consolidated text, including Article 14, is available on Légifrance’s page for Ordinance no. 96-50 of 24 January 1996. A notice that shows CSG, CRDS and possibly CASA should therefore be read line by line. CASA is the additional contribution for solidarity for autonomy; it is not interchangeable with CSG or CRDS.

The S1 matters because it can demonstrate that France is not the state responsible for financing your healthcare. The official French Brexit information explains that, under the relevant coordination arrangements, a pensioner receiving a pension from one state while residing in another can remain covered by the state paying the pension. It also explains that the portable S1 document is used for registration in the competent healthcare system. The page refers to the document as “Le formulaire S1”. In practical terms, an S1 registered with the French caisse primaire d’assurance maladie (CPAM, the primary health-insurance fund) can support the position that the United Kingdom remained the competent state for healthcare costs. The UK-facing overview is also available in GOV.UK guidance on living in France.

That evidence must be matched to the legal wording. An S1 is not proof that every person with a UK pension is outside the French scheme. A person who works in France, receives a French pension, becomes insured through a French activity, or has another basis of compulsory French coverage may have a different position. A person holding a private pension product rather than a statutory or occupational pension may also need to establish how France classifies that payment. A move between systems during the year must be dated. The question is not “Am I British?” but “Which compulsory health-insurance legislation covered me when this contribution was assessed, and what was the nature of the income?”

The distinction is also important because the French administration uses different rules for income from employment and replacement income, for income from assets, and for capital gains. The fact that a person is exempt from CSG and CRDS on one category does not automatically remove a levy on another category. A refund request that mixes a UK pension with rent from a French property or with a sale of shares can be rejected because each amount has a different statutory basis.

B. What did Brexit change, and what does an S1 actually prove?

Brexit did not turn the S1 into a general tax certificate. It changed the legal framework in which healthcare coordination must be analysed. British citizens whose situation was protected by the Withdrawal Agreement may rely on rights acquired before the end of the transition period, subject to the facts and continuity of their position. The Trade and Cooperation Agreement also contains coordination rules for situations beginning after 1 January 2021. The French government guidance describes both routes, but the applicable instrument and the date of the move must be recorded in an individual file.

For a pensioner, the evidence normally starts with the UK decision or certificate that gave rise to the S1, the S1 itself, proof that it was accepted or registered in France, and the dates for which it remained valid. Keep the letter from the UK authority, the CPAM registration confirmation, and any replacement S1 or change-of-circumstances notice. If the United Kingdom stopped being the competent state because you started receiving a French pension or began work in France, the old S1 cannot carry the analysis beyond that change.

The UK side should be checked separately. GOV.UK explains that a person living abroad may be taxed by the country of residence and by the UK, and that the France–UK tax treaty determines where the pension is taxed and how double taxation is relieved. Its guidance says that the treaty will tell you where to pay tax; see GOV.UK’s guidance on tax when living abroad with a pension. The French and UK income-tax question is distinct from the social-insurance condition in Article L. 136-1. A treaty allocation of income tax does not, on its own, answer whether CSG or CRDS is due.

The bilateral treaty should nevertheless be kept in the file. The official French tax administration publishes the France–United Kingdom income-tax convention materials and country guidance through impots.gouv.fr. Use the version relevant to the year and to the type of pension: a UK State Pension, an occupational pension, a private pension and a public-service pension may not be treated identically. The treaty may decide income-tax jurisdiction, while the S1 and the social-security coordination rules inform the health-insurance connection required for social contributions.

Do not transplant the rule for French-source property income into a pension claim. The tax administration’s page for non-residents explains that residents of the United Kingdom can continue to benefit from a CSG and CRDS exemption for certain income from assets where the conditions are met, while the solidarity levy may remain due. That page concerns income from assets and related gains; it is available at impots.gouv.fr’s non-resident social-contributions guidance. A pension paid from the UK is replacement income, not automatically property income. The document and the box on the assessment must be identified before a legal conclusion is drawn.

The same warning appears in the evidential rules. Article D. 136-4 of the Social Security Code identifies an S1 as one possible document for proving affiliation for the exemption connected with certain capital gains on assets. The provision says that the taxpayer can produce “Le formulaire S1” among the listed documents, but the article is located in the rules for exemptions applied to income from assets. Read Article D. 136-4 of the Code de la sécurité sociale as an evidential guide, not as a stand-alone rule that every UK pension is exempt.

The income classification can become difficult where a British resident receives a UK pension, a French pension, a rental profit and a lump sum from a personal pension in the same year. The French tax return may contain several reporting lines. The 2041-GG notice is the French information document for foreign-source employment and replacement income subject to social contributions; the tax administration explains the form and its 2026 version at the official 2041-GG page. Foreign pensions are not necessarily treated like a pension paid by a French caisse, and a capital payment can be treated differently from an annuity. Preserve the exact form, the assessment and the calculation rather than relying on the label used by a bank or pension provider.

Two decisions illustrate why facts and social-security affiliation must be proved. In Conseil d’État, 24 July 2019, no. 416662, the court considered whether a foreign pension could enter the CSG and CRDS base where the claimant also received a French pension and was connected to the French system. That decision should not be copied mechanically into an S1-only case: a French pension and French affiliation may lead to a different result. In Cour de cassation, Second Civil Division, 9 December 2010, no. 09-71.814, the court examined the need to establish the insured person’s effective connection to a compulsory French scheme. These decisions make the evidence question central rather than decorative.

II. How can a British pensioner claim a CSG and CRDS refund?

A. Which evidence, calculation and deadline should be used?

Start with the document that shows the disputed charge. It may be a French income-tax assessment, an additional assessment, a payment notice, a pension statement, or a line on a statement issued by another body. Note the tax year, the date of issue, the amount of CSG, the amount of CRDS, any CASA, the solidarity levy, the income category and the name of the collector. A claim addressed to the wrong body can lose time even where the underlying argument is sound.

For foreign-source employment and replacement income, the French tax administration explains that recovery of CSG and CRDS can be handled through the Direction générale des finances publiques (DGFiP, the French public finances directorate), with the amounts assessed through the tax process. The official 2041-GG material records that CSG and CRDS on foreign-source replacement income are calculated under social-law rules but can be collected by tax assessment. If a pension fund, employer or another organisation made the deduction directly, the same official guidance says that the request should be addressed to the organisation that made the deduction. The public explanation is available in the non-resident guidance, which states that contributions collected by another organisation on pensions should be claimed from the body that made the deduction.

Build the file in chronological order. Include the following items:

• the UK pension award letter or annual pension statement, identifying the paying authority and the type of pension;
• the S1, including the issuing authority, effective date and any replacement or cancellation notice;
• proof that the S1 was registered or accepted for healthcare in France, with the CPAM correspondence and registration date;
• evidence of French tax residence for the relevant year, such as the French assessment and the address recorded with the tax service;
• proof of any French employment, French pension or other compulsory French health-insurance basis, so that the claim deals openly with an adverse fact rather than leaving an unexplained gap;
• the tax return pages and schedules used for the foreign pension, including the 2047 foreign-income return and the 2042 return where relevant;
• the assessment showing the disputed CSG and CRDS, the payment record, and a calculation separating each levy and each pension year; and
• bank details and a clear request for repayment to the person who actually paid the amount.

A certified translation is not automatically required for every document, but the administration must be able to understand the evidence. A short English summary of each UK document, together with the original and a French translation where the wording is material, is safer than sending a large bundle without an index. Give each document a date and a file name. If your S1 is electronic, retain the original download and its metadata. If the document has been replaced, attach both versions and explain the interval between them.

Calculate the claim from the assessment, not from a headline rate. Article L. 136-8 supplies the CSG pension rates, but the taxable base, the household RFR, the year of assessment and the type of pension can alter the amount. CRDS has its own legal basis under Article 14 of Ordinance no. 96-50. CASA and the solidarity levy must be listed separately. A refund claim can ask for CSG and CRDS while accepting that a different levy is legally due. Asking for the whole social-contributions line without explaining the distinction makes the request less precise.

Also check whether the amount relates to a pension paid as a regular annuity or to a lump sum. A personal pension lump sum can have a different income-tax and social-contribution treatment. Do not describe an investment product as a “pension” merely because the provider uses that word in English. Obtain the product rules, the payment statement and the tax reporting line. Where the payment is a foreign public-service pension, check the treaty and the paying-state rules separately from the S1 analysis.

Write the legal ground in a short, ordered way. First, state that you were tax resident in France during the disputed period. Secondly, state the source and nature of the pension. Thirdly, identify the UK S1, its period of validity and the evidence of registration. Fourthly, explain that Article L. 136-1 makes coverage by a compulsory French health-insurance scheme a condition for CSG on replacement income. Fifthly, identify the exact assessment and request reimbursement of the CSG and CRDS charged without that condition being met, while reserving the position on any different levy. Finally, ask the administration to issue a reasoned decision if it disagrees.

The claim should be filed through the secure messaging service attached to the French tax account or by the written channel shown on the assessment. Keep proof of submission, the full text of attachments and the acknowledgement of receipt. If the collector is not the DGFiP, send the claim to the pension fund or organisation that made the deduction and retain proof of delivery. A phone call can clarify which department is competent, but it is not a substitute for a dated written claim.

Time limits deserve particular care. Article L. 190 of the Livre des procédures fiscales (French Tax Procedures Book) defines a contentious tax claim as one seeking correction of an error in the assessment or calculation or the benefit of a statutory or regulatory right. The official text refers to the “réparation d’erreurs commises dans l’assiette ou le calcul des impositions”. It is available at Article L. 190 of the Livre des procédures fiscales.

For ordinary tax claims, the current version of Article R. 196-1 requires presentation no later than 31 December of the second year following the relevant year of assessment, notice or payment, depending on the route used. The key wording is “au plus tard le 31 décembre de la deuxième année suivant celle”. Check the version applicable to the assessment and the legal nature of the deduction at Article R*. 196-1 of the Livre des procédures fiscales. Do not assume that a recent discovery of the S1 restarts the clock. It may explain the error, but it does not automatically create a new claim period.

For example, if a tax assessment put the disputed contribution into recovery in 2025, the general rule may require the claim by 31 December 2027. That example is only a calendar illustration. The actual date must be taken from the assessment, payment record and the version of the rule applying to the claim. Older years may have different procedural details. Submit the claim early enough to correct an incomplete bundle before the deadline.

There is a practical calculation that helps prevent confusion. Make one table with a row for each year and columns for UK pension gross amount, French pension amount, French employment income, CSG, CRDS, CASA, solidarity levy, tax paid, S1 validity and French health-insurance basis. Mark “none” where there is no French pension or employment rather than leaving a blank. Then compare the table with the 2041-GG lines and the assessment. This can reveal that a charge was calculated on the wrong category or that the administration treated one year as covered by France after the S1 had already been accepted.

B. What happens if the administration rejects the refund?

First identify the reason for refusal. A response may say that the S1 is missing, that the document covers a different period, that you were affiliated to France, that the pension is not the category claimed, that the request is late, or that the wrong body was contacted. Each reason requires a different response. Send a targeted reply with the missing document or a legal explanation; do not simply resend the same bundle.

The correct forum depends on the collector. If the DGFiP established or recovered the disputed amount through a French tax assessment, the process is normally a contentious tax claim. If the administration does not give complete satisfaction, Article L. 199 of the Livre des procédures fiscales provides for a challenge before the administrative court in matters covered by the provision. The version in force from 1 September 2026 is available on Article L. 199 of the Livre des procédures fiscales.

Article R*. 199-1 sets the procedural timing for a court action: the claim is generally brought within two months after receipt of the decision on the administrative claim, with a route to court after the administration has remained silent for six months. The official text is at Article R*. 199-1 of the Livre des procédures fiscales. Read the refusal carefully, record the date it was received and obtain advice before the two-month period expires. A tribunal is not a second opportunity to submit an unstructured tax return; the evidence and legal ground should already be organised.

If a social-security organisation or pension body made the decision, the route may instead involve the commission de recours amiable (CRA, the amicable appeal commission) of that organisation. Article L. 142-4 provides that certain contentious claims in social-security matters are preceded by a prior appeal. Its official wording begins: “Les recours contentieux formés dans les matières mentionnées aux articles L. 142-1 … sont précédés d’un recours préalable”. See Article L. 142-4 of the Code de la sécurité sociale and the detailed Légifrance section on the prior social-security appeal. The deadline and recipient shown in the decision must be followed.

Article L. 142-8 states that “Le juge judiciaire connaît des contestations relatives” to the social-security litigation described by the Code. It is available at Article L. 142-8 of the Code de la sécurité sociale. That provision does not mean that every CSG or CRDS dispute belongs before the judicial court. A charge established by the tax administration and a direct deduction by a social-security body can follow different tracks. The identity of the decision-maker is therefore a jurisdictional fact.

The case law gives useful principles but must be applied with care. In Conseil d’État, 8th–3rd chambers sitting together, 9 September 2020, no. 432985, the court considered social levies and the relationship between the contributor and the social-security system. Its reasoning refers to the risk of “verser des contributions à fonds perdus”, meaning paying contributions into a system from which the person cannot obtain the corresponding benefit. That decision concerned a different factual and European-law context, so it is not an automatic ruling for a UK S1 claimant. It does, however, explain why the actual competent social-security system and the purpose of the levy matter.

The post-Brexit analysis must also respect the difference between acquired rights and a new situation. A British citizen who lived in France before 31 December 2020, remained within the Withdrawal Agreement conditions and has a continuing UK healthcare entitlement may have a different file from a person who moved to France in 2023 with a new visa and an S1 issued under the Trade and Cooperation Agreement. The date of residence, the pension source, the S1 legal basis and any French activity should be stated expressly. An administration is more likely to understand a claim that answers those four questions in its first page.

If the refusal says that an S1 proves only healthcare entitlement and not tax treatment, the response should accept the first part and explain the second. The S1 does not allocate income tax. It is evidence of the competent healthcare system. Article L. 136-1 supplies the social-contribution test for replacement income. The France–UK treaty supplies separate income-tax rules. The claim succeeds only if those instruments are connected to the correct income and period. Overstating the effect of the S1 can weaken an otherwise valid request.

If the refusal concerns the income category, obtain the French tax calculation behind the assessment. Ask whether the amount was treated as a pension under the foreign-source replacement-income rules, as a capital payment, or as income from assets. Where the administration has combined several payments, request the allocation by category and year. A refund can be partial. A precise claim for the CSG and CRDS attached to the UK pension is stronger than a general demand for every levy shown on the notice.

If the refusal concerns the deadline, compare the notice date, recovery date, payment date and claim date against Article R*. 196-1 and the relevant provisions for the type of levy. Keep evidence of an earlier informal request, but do not assume that an informal message preserved the formal deadline. If the administration has issued a new assessment or a corrected notice, analyse that event separately. A legal review is particularly useful where several years are involved or where the first response was sent to the wrong department.

If the administration does not respond, silence does not necessarily mean that the claim is lost. The applicable period for court proceedings depends on the route and on the procedural rules cited in the notice. Under the tax route, Article R*. 199-1 refers to the six-month period for bringing a matter before the competent court when no decision has been received. Under the social-security route, the CRA rules and the organisation’s decision control the next step. Record every date and avoid waiting for a second reminder if a court period is approaching.

The final file should contain a one-page chronology, a one-page legal summary, the calculation table, the S1 evidence and the assessment. Put the official links and article numbers in the legal summary, but do not replace documents with hyperlinks. State the result requested: cancellation or refund of the CSG and CRDS charged on the identified UK pension for the identified years, without asking the administration to disregard any levy that is legally distinct. This disciplined presentation also makes it easier for a lawyer to test whether the claim belongs to the tax court, the social-security court, or the collector’s appeal body.

Conclusion

A British pensioner with an S1 may have strong grounds to challenge CSG and CRDS charged on a UK pension in France, but the result depends on the precise social-security connection, the period of S1 coverage, the nature of the pension and the collector’s route. The safest analysis starts with Article L. 136-1, separates replacement income from property income and capital payments, and treats the S1 as time-specific evidence rather than as a blanket Brexit exemption.

Before sending a refund request, identify every line on the assessment, assemble the UK and French healthcare evidence, calculate CSG and CRDS separately from CASA and any solidarity levy, and verify the applicable deadline. Send the claim to the body that actually collected the amount. If the answer is negative, follow the refusal’s procedural route promptly: a DGFiP tax claim may lead to the administrative court, while a social-security decision may require a prior appeal before the competent social-security court route.

Official sources checked: the French Social Security Code and Tax Procedures Book on Légifrance, the consolidated CRDS ordinance, the French government Brexit guidance, impots.gouv.fr’s foreign-income and non-resident guidance, and GOV.UK’s pension-tax guidance. The cited court decisions are Conseil d’État, no. 416662, Conseil d’État, no. 432985, and Cour de cassation, no. 09-71.814.