- Every UK bank account, ISA, SIPP, investment platform or crypto wallet you hold must be declared to France via Form 3916 (or 3916-bis for crypto) — every single year it exists, whether it earned a penny or not
- This is separate from declaring income — you can owe zero tax on an account and still face a fine for not declaring its existence
- The fine is €1,500 per undeclared account, per year — and France finds out anyway, through automatic data-sharing with the UK
- SIPPs often catch people out: they're treated as a foreign financial account, not as a "pension" — so they go on this declaration as they are considered an investment tool
You don't need to have moved any money, earned any interest, or even logged in this year. If a UK account existed — was open, held, used, or closed — at any point during the tax year, France wants to know it exists. Not what's in it. Not what it earned. Just that it's there.
This catches people who've already filed correctly for years on the income side. You've declared your pension on Form 2047, ticked the right boxes on Form 2042 — and still missed this, because it isn't about income at all. It's a separate compliance requirement, and it applies even when the account did not make any money or is empty.
What actually counts as a "foreign account" here
Under French law, you must declare any account opened, held, used, or closed abroad during the tax year — current accounts, savings accounts, investment platforms, and digital asset accounts all count. The rule is broader than most people expect, and it doesn't care about the balance.
Here's where it gets people, type by type:
Standard UK current and savings accounts. The obvious one — and the one most people remember. Yes, even your everyday Barclays or NatWest account.
ISAs. These are foreign investment accounts as far as France is concerned, regardless of how tax-free they are in the UK. France doesn't recognise the ISA wrapper, and the account itself still needs declaring. For how ISA income is taxed, see ISAs and SIPPs in France: What UK Expats Need to Know About Tax.
SIPPs and other private pensions. This is the one that genuinely surprises people — including those who've been filing carefully for years. A SIPP (Self-Invested Personal Pension — a flexible UK private pension you manage and invest yourself) isn't treated like your State Pension or a company pension. France classes it as a financial account you hold abroad. It doesn't matter whether you're drawing it down, leaving it untouched, or just waiting to decide — if the account exists, it goes on this declaration in its own right, separately from however you're declaring any income you do take from it. For how the income side is taxed, see ISAs and SIPPs in France: What UK Expats Need to Know About Tax.
Premium Bonds and other NS&I products. Still a foreign account. Still needs declaring, even though Premium Bonds famously pay no guaranteed "interest" in the conventional sense.
Investment platforms and brokerages (Hargreaves Lansdown, AJ Bell, and similar). Any brokerage account held with a provider based outside France counts, and any gains or income from it has its own separate declaration on top of this one.
Crypto wallets and exchange accounts. These go on a different form — Form 3916-bis rather than 3916 — but the principle is identical: existence must be declared, account by account, every year. See Cryptocurrency and French Tax: What UK Expats Need to Know for how the income and gains side works.
And this is what most people get wrong: they assume the obligation only kicks in if the account did something — paid interest, grew in value, received a transfer. It doesn't. An account with a zero balance that wasn't formally closed before the start of the year still needs declaring.
Which form, and where it goes
Standard foreign accounts — bank accounts, ISAs, SIPPs, brokerage accounts — are declared on Form 3916. Digital asset accounts — crypto wallets and exchanges — are declared on Form 3916-bis. Both are filed alongside your main return, Form 2042, as an annex. If you're still getting your head around how the French return fits together, How the French Tax System Works: A Plain-English Overview is the place to start. You complete one declaration per account, every year the account exists, whether or not anything happened in it.
If you're filing online, the 3916/3916-bis section appears as its own annexe inside the online declaration process — you'll list each account one at a time and validate before moving to the next. You're not asked for the balance or the amount invested. Only that the account exists, who it's with, and where. Unfamiliar with a term like "foyer fiscal" or "RFR"? Check the French Tax Glossary: Essential Terms for UK Expats.
Taxpert's filing assistant lists all the accounts you need to declare and walks you through the 3916 entries alongside your income declaration. Try Taxpert →
Common mistakes
- Assuming "no income, no declaration." The existence declaration and the income declaration are two separate obligations.
- Treating a SIPP as "just a pension." A SIPP doesn't stop being a foreign financial account just because it's sitting untouched. If you're not drawing anything from it yet, its existence means it must be declared as a foreign account.
- Forgetting accounts you barely touch. An old savings account you haven't logged into in years, or a joint account you're a signatory on but don't actively use, still counts if it was open at any point in the year.
- Assuming a zero balance means no obligation. Unless the account was formally closed before the tax year started, a dormant account with nothing in it still needs declaring.
- Believing it'll go unnoticed. France receives your UK account information automatically through international data-sharing arrangements between tax authorities. This isn't a "might get caught" situation — it's closer to "already on file, just not yet matched to a fine."
What it costs if you don't
The standard penalty is €1,500 per undeclared account, per year. Miss three accounts for two years running, and that's not one fine — it's potentially nine separate ones, because each account and each year is counted separately.
If the account is held in a state or territory that hasn't signed an administrative assistance agreement with France, the fine rises to €10,000 per account, per year. For digital asset accounts under Form 3916-bis, the standard penalty is €750 per undeclared account (or €125 for a smaller error or omission, capped at €10,000 per declaration) — rising to €1,500 and €250 respectively for non-cooperative jurisdictions.
There's a sting in the tail beyond the fine itself: the normal three-year window the tax authorities have to query your return extends to ten years specifically for undeclared foreign accounts. That's a long time for an old, forgotten account to resurface.
If you've realised you've missed one or more years, correcting it voluntarily — before any enquiry starts — generally leads to a more lenient outcome than waiting to be caught. It's not a guarantee, but it's consistently the better position to be in.
Frequently Asked Questions
Do I need to declare a UK account that earned no interest at all?
Yes. The declaration is about the account's existence, not what it earned. An account that paid zero interest still needs to be listed on Form 3916 every year it was open.
Is my SIPP declared on Form 3916, separately from my pension income?
Yes. Your SIPP itself goes on Form 3916 as a foreign financial account. The income you draw from it is declared separately, typically alongside your other pension income — the two are different obligations, not one combined entry.
What about a joint account where I'm not the main account holder?
It can still need declaring. The obligation can extend to an account you're simply a signatory on or able to use, even if you're not the named account holder — so don't assume a secondary name lets you off the hook.
Does my Wise or Revolut account count as foreign?
Yes, in most cases. Wise and Revolut accounts are typically domiciled outside France, which makes them foreign accounts for this purpose — even if you only use them for small, everyday transfers. See Using Wise in France? Here's What You Need to Declare for more on Wise specifically.
What if I've never declared my accounts and have been here for years?
You can correct this voluntarily rather than wait for it to be picked up. Submitting the missing declarations yourself, before any enquiry, generally puts you in a better position on penalties than having it found for you.
Is crypto declared the same way as a bank account?
Not quite — digital asset accounts use Form 3916-bis instead of Form 3916, but the underlying principle is the same: you're declaring the account's existence, not its value, and it's due every year the account exists.