ISAs and SIPPs in France: What UK Expats Need to Know About Tax (2026)

Two of the most common UK financial vehicles — the ISA and the SIPP — work very differently in France. The ISA tax-free wrapper doesn't exist in French law. The SIPP is treated as a private pension. Here's what each means for your French tax return.

France doesn't recognise the ISA wrapper. The tax-free status you built up in the UK stops the moment you become French tax resident — and the income inside your ISA becomes fully taxable in France, whether you withdraw it or not.

Most people find this out late. If that's you, you're not alone — and this article will tell you exactly what to declare and where.

SIPPs are simpler: France treats them as a private pension. The rules are the same as for any UK private pension drawdown. We'll cover both below.

For the broader picture on how investment income is taxed in France, see our guide to PFU vs Progressive Tax: Which Is Better for Your Investment Income?. For private pension income including SIPP drawdown, see UK Private Pension: How It's Taxed in France.

ISAs: The Tax-Free Wrapper That Isn't

In the UK, an ISA (Individual Savings Account) shelters interest, dividends, and capital gains from tax entirely. The income grows tax-free and can be withdrawn tax-free. That's the whole point of the wrapper.

France does not recognise this wrapper. There is no provision in French tax law that grants ISAs any special status.¹ Once you are a French tax resident, the income and gains generated inside your ISA are taxable in France in exactly the same way as income and gains from any other investment account.

This means:

• Interest from a Cash ISA is taxable as investment income
• Dividends from a Stocks and Shares ISA are taxable as dividend income
• Capital gains from selling shares or funds inside a Stocks and Shares ISA are taxable as capital gains

This is one of the most common surprises for UK expats. The ISA wrapper is a feature of UK domestic tax law — it has no legal effect in France.¹

What Rate Applies to ISA Income

All three types of ISA income — interest, dividends, and capital gains on securities — are subject to a Flat tax at 31.4% called the PFU (Prélèvement Forfaitaire Unique). It is made up of 12.8% income tax plus 18.6% in social charges (as at 2026).

France gives you a choice about how your investment income is taxed. The default is a flat rate of 31.4% on everything — straightforward, no calculation needed.

The alternative is to use the same sliding scale that applies to your regular income — where lower earners pay a lower percentage. If your overall income is modest, this can work out cheaper than the flat rate.

The catch: it's all or nothing. You can't apply it just to your ISA income — it switches to the sliding scale for all your investment income that year.

See our PFU vs Progressive Tax guide for how to assess this.

If you hold an S1: Your rate is lower. Instead of the full 31.4%, you pay 12.8% income tax plus a reduced 7.5% healthcare contribution — a combined rate of 20.3%. This is because S1 holders are covered by the UK NHS rather than the French healthcare system, so the French healthcare contribution doesn't apply in full.

How to Declare ISA Income

ISA income is declared in exactly the same way as income from any other UK investment account. There are no special boxes or forms — you simply declare in the same way as dividends and interest.

Dividends from a Stocks and Shares ISA:

• Form 2047, Section 2, Line 220 (Revenus n'ouvrant pas droit à un crédit d'impôt — income not giving rise to a foreign tax credit) — enter the gross dividend amount here. Line 221 is a calculated total that populates automatically — do not enter a figure there. Line 222 carries the total forward to Box 2DC on Form 2042
• Form 2042, Box 2DC — total gross dividends (all sources combined)
• If UK tax was withheld at source (unusual for most dividend payments to French residents) use Route B on Form 2047 Section 2 and claim the treaty credit in Section 7 → Box 8VL on Form 2042 C

Interest from a Cash ISA:

• Form 2047, Lines 250, 251 and 252 — enter the gross interest amount on Line 250 and repeat the same figure on Lines 251 and 252
• Form 2042, Box 2TR — total gross interest (all sources combined)
• If you opted for the progressive scale (Box 2OP) and do not hold an S1: also enter your interest in Box 2BH on Form 2042 — this enables the 6.8% CSG deductible from next year's taxable income. S1 holders do not use Box 2BH.
• Note: there is no French tax credit mechanism for UK interest withheld at source — always declare the full gross amount and reclaim any UK withholding directly from HMRC

Capital gains from selling within a Stocks and Shares ISA:

• Form 2042, Box 3VG — net capital gains on securities
• Capital losses can be carried forward for up to 10 years and offset against gains of the same type in future years

Note on totals: Boxes 2DC, 2TR, and 3VG represent your household total across all accounts and all sources — UK bank accounts, ISAs, other foreign accounts. You don't create separate entries for ISA income. It all goes into the same boxes as your other investment income.

S1 holders: Tick Box 8SH (Declarant 1) or 8SI (Declarant 2) on Form 2042 C under Revenus de source étrangère — cotisations sociales. This tells the tax office you're covered by the UK NHS — so instead of the full 18.6% healthcare contribution, you pay the reduced 7.5% rate on your investment income.

If only one partner in your household holds an S1, you also need to enter that partner's share of your total investment income in Box 8RC. This separates their income from their partner's so each is taxed at the right rate.

If you have income from multiple accounts — ISAs, UK savings, foreign bank accounts — this is where it gets fiddly. Converting each payment to euros, adding it all up, and working out which boxes to use takes time and it's easy to miss something. Taxpert's filing assistant does all of this for you. Enter your accounts once and it handles the rest.

The Form 3916 Declaration for ISA Accounts

You are obliged to tell the French tax office that your ISA account exists. This is done on Form 3916, filed every year — even if you had no income from the account that year.

The penalty for missing this is €1,500 per account per year. Not per household — per account. A Cash ISA and a Stocks and Shares ISA are two separate accounts, each needing its own Form 3916 entry. If you have a Junior ISA in a child's name and they're part of your household for tax purposes, that needs declaring too.

When filing online, tick Box 8UU on Form 2042 C to confirm that Form 3916 has been completed. This applies to all foreign accounts — ISAs, SIPPs, and UK bank accounts alike.

Should You Keep Your ISA?

Once you're France-resident, your ISA has no tax advantage here. The wrapper France ignores entirely.

The only reason to keep it is, if you might return to the UK one day — the tax-free status would kick back in when you do. If that's not on the cards, some advisers suggest a French assurance vie as a more tax-efficient home for your savings — it has its own tax benefits after eight years. But closing an ISA is permanent. You can't put the money back in later. Take advice before you act.¹

SIPPs: Treated as a Private Pension

A SIPP (Self-Invested Personal Pension) is treated in France as a private pension — specifically as a pension de retraite de source étrangère (foreign source retirement pension). France does not distinguish between a SIPP and any other private pension scheme for tax purposes.²

This means:

• Regular withdrawals from a SIPP are declared as pension income — on Form 2047 Line 12 and Form 2042 Box 1AM/1BM. France automatically reduces the taxable amount by 10% before calculating your bill — this is a standard deduction the French tax system applies to all pension income, and it happens automatically.
• While your SIPP sits untouched, any growth inside it is not taxable in France. You only pay tax when you actually take money out.

Taking your whole SIPP as a lump sum: A lower flat rate of 7.5% may apply, but only if all three conditions are met:

• It's a one-off withdrawal of the entire pot — not regular drawdown
• Your pension scheme qualifies under French rules
• You didn't make any tax-deductible pension contributions while living in France (for most UK SIPP holders this isn't an issue — you can't get UK tax relief on contributions once you've left the UK)

If conditions are met, the 7.5% rate applies after the 10% allowance. Full details in our Pension Lump Sums guide.

Gains within an undrawn SIPP: While your SIPP remains undrawn, internal gains are not taxable in France. They only enter the French tax calculation when you take income or a lump sum. No annual declaration of notional gains is required.

UK tax on SIPP income: Under Article 17 of the UK-France treaty, private pension income — including SIPP drawdown — is taxable only in France. You should notify HMRC that you are a French resident so UK tax is not deducted at source. If UK tax is being deducted in error, declare the full gross amount on your French return and reclaim the UK tax from HMRC.

The Form 3916 Declaration for the SIPP Account

Like ISAs, SIPPs held with UK providers are foreign financial accounts and must be declared on Form 3916 each year — including years in which no drawdown is taken. The account exists and must be declared. The same €1,500 per account per year penalty applies for failure to declare.

Common Mistakes

1. Assuming ISA income is tax-free in France. It isn't. The UK tax-free wrapper has no legal effect in French law. All income and gains generated inside an ISA are fully taxable in France in the year they arise.

2. Not declaring ISA income because it wasn't paid out. If your Stocks and Shares ISA reinvests dividends automatically, those dividends are still taxable in France in the year they are credited to the account — not when you eventually withdraw the money. Reinvested income is still income.

3. Declaring SIPP drawdown as capital rather than pension income. Regular drawdown from a SIPP is pension income — not a capital withdrawal. It goes on Form 2047 Line 12 and Box 1AM/1BM, not on the capital gains forms. Treating it as capital can result in the wrong rate being applied.

4. Forgetting Form 3916 for ISA and SIPP accounts. The income declaration and the account existence declaration are two entirely separate obligations. Declaring the income correctly does not satisfy the Form 3916 requirement — you need to do both every year the account exists.

5. Continuing to pay into a UK ISA after becoming France-resident. You cannot pay into a UK ISA if you are not a UK tax resident. Contributions made as a French resident are not permitted under UK ISA rules — any such contributions would need to be removed. This is a UK rule, not a French one, but it's worth flagging.

6. Not reclaiming UK tax wrongly withheld on SIPP drawdown. If your SIPP provider is still deducting UK income tax, submit the HMRC double taxation relief form and reclaim it. Always declare the gross amount on your French return.

Frequently Asked Questions

I have a large Cash ISA. Do I need to declare the interest every year even if I don't touch it?

Yes. Interest credited to a Cash ISA is taxable in France in the year it arises, regardless of whether you withdraw it. The fact that it stays inside the ISA wrapper makes no difference — France looks through the wrapper to the underlying income.

I have a Stocks and Shares ISA that reinvests dividends automatically. Do I still need to declare them?

Yes. Reinvested dividends are still dividends — they are income in the year they are credited, even if they are immediately used to buy more units. You should receive an annual statement from your ISA provider showing dividends paid or reinvested during the tax year. That figure is what you declare on your French return.

Does the taper relief on shares (50% after 2 years, 65% after 8 years) apply to shares inside an ISA?

No. The taper relief available on capital gains for shares held directly applies to shares held outside a tax wrapper. Shares held inside an ISA are not eligible for this relief — the gains are taxable in full. This is another reason why the ISA wrapper provides no advantage in France, and may in some cases be less efficient than holding shares directly if you plan to hold for the long term.

My SIPP is still fully invested and I haven't started drawdown. Do I have any French tax obligations now?

Your main obligation is the annual Form 3916 declaration of the SIPP as a foreign account. You don't need to declare any income while no drawdown is taken and no lump sum is withdrawn. Gains growing inside the undrawn SIPP are not separately taxable — they only come into the French tax calculation when you draw income.

I have both a UK ISA and a French assurance vie. Do I declare them differently?

Yes — completely differently. The ISA is a foreign account (Form 3916) and its income is declared as investment income in the normal boxes. The French assurance vie has its own specific declaration route and tax treatment, including favourable rates after eight years. They are treated as entirely separate income types on your French return.

Can I transfer my ISA to a French assurance vie?

You can close your ISA and invest the proceeds in an assurance vie — but you cannot transfer directly. Closing an ISA means you lose the UK tax-free wrapper permanently, so this is an irreversible decision. Whether it makes financial sense depends on your individual situation, your plans regarding the UK, and the specific assurance vie product. Take regulated advice before acting.

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