You moved to France, you pay your French taxes, and one evening you log in to your British pension forecast and discover holes: three missing years from that spell of contracting, two from the year you left, one from the career break. Each empty year is money lost every week for the rest of your retirement, and the question that follows is brutally practical: can you still buy those years back while living in France, what will each year cost, and once the bigger pension arrives, who taxes it and who takes social charges from it? Since 6 April 2026 the answer to the first question has changed completely, because the cheap expatriate route is gone. This guide walks the whole chain in order: how the new State Pension counts your years, how voluntary National Insurance contributions work from France under the post-April-2026 rules, how your pension keeps its annual increase in France and what deferral buys you, and how France taxes the resulting pension under the 2008 double tax treaty, including the court-tested credit machinery and the social-charges trap that turns on one document, your health cover. Every French term is explained as it appears, because this article is written for a British reader dealing with two systems at once.
A qualifying year is a tax year in which you paid enough National Insurance, or received National Insurance credits, for the year to count toward your State Pension. National Insurance contributions come in classes: Class 1 is what employees pay through payroll, Class 2 was the flat-rate contribution of the self-employed, and Class 3 is the voluntary contribution anyone can pay to fill gaps. The convention fiscale franco-britannique, the France-United Kingdom double tax treaty signed in London on 19 June 2008, decides which of the two countries may tax each type of income. The CSG (contribution sociale généralisée) and the CRDS (contribution pour le remboursement de la dette sociale) are the French social charges levied on income alongside income tax. The S1 form is the certificate by which the United Kingdom, which pays your State Pension, also takes charge of your healthcare costs in France. PUMA (protection universelle maladie) is the French universal health cover for residents who are not covered elsewhere. Keep these six definitions in mind and the rest follows.
I. Counting your years and buying back the missing ones from France
A. How the new State Pension measures your record and what each gap costs you
Anyone whose National Insurance record started after April 2016 is under the new State Pension, and the arithmetic is fixed by statute and published on GOV.UK: Anyone whose National Insurance record started after April 2016 needs 35 qualifying years to earn the full rate of new State Pension (GOV.UK, new State Pension – what you will get). The full rate is stated on the same page: The full rate stands at £241.30 a week (GOV.UK, new State Pension – what you will get). Below the full rate, each qualifying year is worth one thirty-fifth of that amount, so a record of 28 years pays roughly four-fifths of the full rate, and the floor is equally explicit: At least 10 qualifying years on your National Insurance record are needed to get any new State Pension at all. Nine years or fewer means no new State Pension at all, which is why topping up from nine to ten years is the single highest-value purchase in the system, and why moving from, say, 31 to 35 years buys a permanent weekly increase for life.
If your record started before April 2016 the picture has one extra layer, the old contracting-out system under which you or your employer paid reduced National Insurance while building a workplace pension instead. GOV.UK warns that people who were contracted out usually need more than 35 qualifying years to reach the full rate of new State Pension, and adds that Additional State Pension built before 2016 can produce a protected payment above the full rate. Before spending a penny on voluntary contributions, get your personal numbers from the only source that matters: your State Pension forecast, backed by the Future Pension Centre if you are below State Pension age, or the International Pension Centre if you have reached it or will do within six months. The forecast tells you which years are gaps, which gaps are fillable, and whether filling them actually raises your pension, because some years are not worth buying, for example a year that would take you past the full rate, or a year in a period where you already hold the equivalent of a full record through credits.
The cost of one year is the Class 3 weekly rate multiplied by 52, and the rate GOV.UK currently publishes is the published Class 3 rate of £18.40 a week, which puts a full year at roughly £957. Set against a pension gain of one thirty-fifth of £241.30 a week, about £6.89 a week or £358 a year every year for life, indexed, the payback on a purchased year is typically around two and a half to three years of pension pictures. That comparison is the whole commercial logic of topping up, and it explains why the April 2026 reform matters so much: the bargain option that made this calculation spectacular for expatriates has been abolished for future years abroad, as the next section explains, so every gap year from now on is priced at the full Class 3 rate and the decision has to be made with open eyes and within the time limits.
Two cautions before you pay. First, voluntary contributions have payment deadlines, and late payment can mean paying a higher rate or losing the year altogether, so check the rates and deadlines pages on GOV.UK for the exact window of each tax year you want to fill, and note the special transitional deadlines described below for people caught mid-application by the 2026 reform. Second, pay only for years that increase your pension; the International Pension Centre will confirm this for people at or near pension age, and the Future Pension Centre for everyone else. Buying a year that the forecast says adds nothing is the most common and most avoidable waste in this system, and no refund procedure makes it painless. With your forecast in hand and the cost per year understood, the next question is which class you are allowed to pay from France, and that is where the ground shifted in April 2026.
B. Voluntary Class 3 from France since April 2026: the 10-year test, the cost, and the CF83 application
Until 5 April 2026, a British resident of France could pay voluntary Class 2 contributions for years spent abroad at the low self-employed rate, provided they had previously lived in the United Kingdom for three years in a row or paid contributions for at least three years, had worked in the United Kingdom immediately before leaving, and were working abroad. That door is now closed for future years. GOV.UK states the new position without ambiguity: voluntary Class 2 contributions are no longer payable for time abroad (GOV.UK, voluntary National Insurance if you live or work abroad) for the 2026 to 2027 tax year onwards. Only Class 3 remains available for time spent abroad after 5 April 2026, and the entry conditions have been toughened at the same time. To pay Class 3 for time abroad you must now have either having previously lived in the UK for 10 years in a row or having paid 10 years of qualifying National Insurance contributions in total, where qualifying contributions mean Class 1, 2 or 3 paid or treated as paid while in the United Kingdom, certain contributions paid while working abroad under a social security agreement, Class 1 paid by posted workers for the first 52 weeks abroad, or Class 2 paid by volunteer development workers, while any other voluntary contributions paid for other periods abroad and National Insurance credits are expressly excluded from the count.
The practical effect is a two-tier population. If you lived in Britain for a decade or built ten years of contributions before moving to France, which covers most people who worked a normal career before relocating, you can keep buying Class 3 years from France indefinitely at the published rate of £18.40 a week (GOV.UK, voluntary National Insurance – rates). If you left young, after a short career, and never reached either ten-year marker, you are locked out of voluntary contributions for future years abroad altogether, and your only remedy is to check whether past years already on your record, or future return to the United Kingdom, since the guidance notes that these stricter rules fall away once you return to live or work in the UK, can carry you to the ten-year floor that unlocks any pension at all. This is the single most important status check of this article: count your ten before you plan anything else.
A transitional shelter exists for people who were already in the system when the reform hit. GOV.UK provides that it remains possible to pay Class 3 for periods spent abroad under the previous rules, the ones that ended on 5 April 2026,, with the old three-year test, but only if all three of the following are true: you applied to pay voluntary Class 2 or Class 3 for the 2024 to 2025 or 2025 to 2026 tax year on or before 5 April 2026, you pay or have paid those contributions on or before 5 April 2027, and you apply for the 2026 to 2027 year on or before 5 April 2027. Miss any limb and the shelter collapses. The application itself goes through form CF83: applications for time abroad go through form CF83, the dedicated HMRC form for people abroad, and the two advisory bodies divide the work as quoted above, the Future Pension Centre before pension age and the International Pension Centre at or near it, because they will check your record for gaps and tell you the amount to pay. Apply on paper early, keep proof of posting and of payment, and diary the 5 April 2027 payment deadline if the transitional rules cover you, because a missed deadline under this reform is not a delay, it is a lost year.
One related trap deserves a paragraph: the years 2006 to 2016 and the special extended deadlines that once allowed very old gaps to be filled have their own cut-off history, and the old-years window that ran to April 2025 is over. Do not assume that any gap on your record is still buyable; some are now permanently closed, and the only reliable answer is the one tied to your National Insurance number from the forecast and the pension centres. And a final warning for couples: each spouse owns a separate National Insurance record, and one partner’s full record does nothing for the other, so run the whole exercise twice, once per person, because the surviving-spouse inheritance of State Pension is limited and derived rights from a husband’s or wife’s record belong largely to the old basic-pension world, not to the new State Pension you are building now.
II. Receiving the bigger pension in France and paying French tax on it
A. Annual increases in France, deferral uplift, and where the money lands
The good news first, because it surprises many new arrivals: your British State Pension is not frozen in France. GOV.UK lists the countries where the pension rises each year, and France qualifies twice over: Your State Pension rises each year only if you live in one of the listed places (GOV.UK, State Pension if you retire abroad – rates): the European Economic Area (EEA), alongside Gibraltar, Switzerland and listed agreement countries, while Outside those listed countries, no yearly increase is paid. France is in the European Economic Area, so the triple lock and its successor uprating rules follow you to the Dordogne as they would to Dundee, and every voluntary year you buy is a year of an indexed pension, not a fixed one. That indexation is what makes the payback calculation in section I so favourable: £358 a year today becomes more in nominal terms with each uprating, for life. Tell the Department for Work and Pensions your French address promptly when you move, and report changes of bank account through the proper channel, because pension payments to a French bank in euros involve exchange timing you should understand, and a payment gone to a closed British account is an administrative ordeal, not a legal problem.
Deferral, postponing your first claim past State Pension age, is the second lever, and its price is published with unusual candour. You must defer at least nine weeks to earn anything, and then every 9 weeks of deferral adds 1% to the regular weekly pension payment for life (GOV.UK, deferring your State Pension), which which builds to just under 5.8% for every 52 weeks of deferral. The worked example uses the current full rate: the official example takes the £241.30 full rate: 52 weeks of deferral adds £13.99 a week, and 104 weeks adds £27.99 (11.6%). GOV.UK then adds the sobering counterpart: recovering 52 weeks of deferred full pension takes over 15 years of receipt, with about a year more for each extra deferred year. Deferral suits the healthy person still earning in France who does not need the money; it punishes the person who defers without understanding break-even. Note that deferral extra pension is taxable like the pension itself, and that the French tax analysis below applies to the uplift exactly as it applies to the base pension, because France taxes the pension you actually receive.
Two household points complete the receipt side. First, consider the survivor: the new State Pension has only limited inheritance between spouses compared with the old system, so a couple that built its retirement plan on one big record should take advice on what, if anything, passes on death, and read it alongside our guide to the surviving spouse’s rights over the French home. Second, keep your British and French paperwork aligned: the same name, the same date of birth, the same address history on both sides of the Channel, because a mismatch between your DWP file, your French tax return and your health registration is how files get suspended and how double payments and recovery notices are born. The pension, once topped up, uprated and claimed, then meets the French tax system, and that is where the treaty takes over.
Readers who want the companion picture, how the pension once in payment is declared year by year and when social charges fall away, will find it in our detailed guide to where your UK State Pension is taxed and how to declare it in France, and those juggling a personal pension alongside the state one should read our analysis of how each private-pension withdrawal is taxed, declared and challenged. If you live between both countries and each claims you as its tax resident, the tie-breaker rules decide everything, as explained in our guide to dual tax residence and the fixer test.
B. French income tax, the treaty credit machinery, and the social-charges question your health cover decides
You are a French resident for tax purposes as soon as France holds your home or your main place of stay, or you work here otherwise than incidentally: article 4 B provides that “Sont considérées comme ayant leur domicile fiscal en France au sens de l’article 4 A : a. Les personnes qui ont en France leur foyer ou le lieu de leur séjour principal ; b. Celles qui exercent en France une activité professionnelle” (CGI, art. 4 B). French residents are taxed on worldwide income; article 4 A of the Code général des impôts, the French tax code, provides that “Les personnes qui ont en France leur domicile fiscal sont passibles de l’impôt sur le revenu en raison de l’ensemble de leurs revenus.” which means residents are liable to income tax on all of their income, wherever it arises (CGI, art. 4 A). Pensions are expressly inside the charge: article 79 states that “Les traitements, indemnités, émoluments, salaires, pensions et rentes viagères concourent à la formation du revenu global servant de base à l’impôt sur le revenu.” Capital lump sums are treated the same way: “Il en est de même des prestations de retraite servies sous forme de capital.” (CGI, art. 79). The treaty then allocates the taxing right, and for an ordinary State Pension or private pension it gives it to France alone. article 18 of the 2008 treaty reserves pensions paid to a resident in respect of past employment to the residence state, subject only to the government-service exception of article 19, paragraph 2. The French tax administration confirms the mechanism from the British end in its official commentary on the treaty: British tax withheld at source on private pensions of British source has been relieved since 1 January 2012 under a dedicated application procedure (BOFiP, convention France-Royaume-Uni, avantages conventionnels). GOV.UK states the same logic from the other shore: residence in a country holding a British double-taxation agreement can spare you paying tax twice, and each country’s tax treaty tells you where to pay tax (GOV.UK, tax when you get a pension and live abroad). In plain terms, a British State Pension paid to a French resident is taxable only in France, so the United Kingdom does not tax it, there is no double taxation to relieve, and the pension is simply declared on the French return, foreign income first, then carried into the taxable base, with the treaty as your authority if the tax office ever queries why no British tax was paid.
The computation in France then follows the standard pension path. Article 158, 5, a of the tax code provides that “Les pensions et retraites font l’objet d’un abattement de 10 % qui ne peut excéder 4 439 €”, with a minimum of 454 euros per pensioner, figures revised yearly with the tax scale (CGI, art. 158). The 10 per cent allowance, capped and floored, applies to the State Pension exactly as it applies to a French pension, and it is one of the quiet advantages of French residence: the same pension costs less in income tax in France than its gross suggests, before the progressive scale does its work. Article 197 of the tax code then sets the progressive scale: “il est fait application des règles suivantes pour le calcul de l’impôt sur le revenu”, with tax computed “en appliquant à la fraction de chaque part de revenu qui excède 11 600 €” at rates running from 11 to 45 per cent (CGI, art. 197). One exception must be isolated because it reverses everything: government service pensions. Under article 19, paragraph 2 of the treaty, pensions paid by a contracting state for government service stay taxable in the paying state, unless the recipient is both resident and national of the other state without holding the paying state’s nationality, in which case only that other state taxes; the treaty collection on GOV.UK points every reader to the same answer: your country’s tax treaty tells you where to pay tax (GOV.UK, tax treaties). A British civil-service, military, police or local-authority pension paid from the United Kingdom to a British national living in France therefore stays taxable in the United Kingdom, and France eliminates the resulting double taxation through its credit method rather than by taxing again.
That credit method is not a vague promise; it was construed for this very treaty by the Conseil d’État, France’s supreme administrative court, in an opinion of 12 February 2020, no. 435907, on questions referred by the Cergy-Pontoise administrative court. The court first quotes article 2 of the treaty, under which the French taxes covered include income tax and, expressly, “(v) les contributions sociales généralisées” and “(vi) les contributions pour le remboursement de la dette sociale”, meaning the CSG and the CRDS are treaty taxes like any other (CE, avis, 12 févr. 2020, n° 435907). It then quotes article 24, paragraph 3, under which a French resident gets a tax credit equal, for income covered by sub-paragraph (ii), to the British tax paid, capped at the French tax on that income, and for other income, to the French tax itself provided the resident “soit soumis à l’impôt du Royaume-Uni à raison de ces revenus”. Three holdings matter for pensioners. First, the phrase “nonobstant toute autre disposition de la présente Convention” does not let France refuse the credit on social charges on the ground that Britain has no equivalent of the CSG. Second, nothing restricts the credit to progressively taxed income, since the treaty itself provides calculation rules for both proportional and progressive French tax. Third, and most usefully, the condition of being subject to British tax means the income must be included in the British tax base without exemption by status, but “cette condition n’exige pas que les revenus en cause aient été soumis à une imposition effective”, so a pension within the British base but paying no British tax in fact still qualifies. Keep this opinion number in your file; it is the authority you cite if a credit is ever denied on one of these three grounds.
Social charges are the last and most personalised layer, because they turn on health cover, not on the pension. Article L. 136-1 of the Code de la sécurité sociale, the social security code, makes liable to the CSG on employment and replacement income “Les personnes physiques qui sont à la fois considérées comme domiciliées en France pour l’établissement de l’impôt sur le revenu et à la charge, à quelque titre que ce soit, d’un régime obligatoire français d’assurance maladie”, that is, people who are both treated as French-resident for income tax and covered by a compulsory French health scheme (CSS, art. L. 136-1). Both limbs must be met. A British State Pensioner who holds an S1 is registered with the French health fund but remains chargeable to the United Kingdom, which is not being covered by a French scheme in the sense of the statute, and that is why S1 holders are generally outside French social charges on the British pension, while a pensioner affiliated to PUMA, the French universal cover, meets both limbs and pays. The administrative courts police exactly this boundary: the Lyon administrative court of appeal held on 13 August 2025, no. 24LY03019, after cassation and remand (Conseil d’État, 25 October 2024, no. 473997), that a Swiss pension paid to a person domiciled in France and covered by a French compulsory scheme was properly subjected to CSG and CRDS, rejecting the European-coordination defence and dismissing the claim in full (CAA Lyon, 13 août 2025, n° 24LY03019). The lesson of the Lyon ruling is simple: status decides. So get your S1 registered with the CPAM, the French health fund, before the pension starts, keep the attestation proving which state bears your health costs, and if a social-charge bill arrives that your cover says should not exist, challenge it first by administrative claim and then before the administrative court, citing your cover, article L. 136-1 and the treaty, within the claim windows that run from each assessment.
Conclusion
The chain is now complete and each link has a number. Count your qualifying years against the 35-year and 10-year markers at the £241.30 full rate; buy the missing ones through Class 3 at £18.40 a week if you meet the 10-year residence or contributions test, through form CF83, minding the 5 April 2027 transitional deadlines if you applied before the reform; collect the pension with its annual increase in France and price any deferral at 1 per cent per nine weeks against the fifteen-year break-even; declare the pension in France under articles 4 A, 79 and 158 with the 10 per cent allowance; allocate taxing rights under articles 18 and 19 of the 2008 treaty; defend any credit under article 24 with the Conseil d’État’s opinion no. 435907; and settle social charges under article L. 136-1 according to whether your health cover is an S1 or PUMA, with the Lyon appeal court’s 2025 judgment as the map of the boundary. Do the forecast this month, because every deadline in this system rewards the early and punishes the late, and the years you can still buy are worth more than any other purchase your retirement will ever offer.