Are Shares and Investment Portfolios Subject to French Inheritance Tax? (2026)

• A personal share dealing account or GIA is an ordinary estate asset for French inheritance tax — it gets no special treatment, unlike assurance-vie or a SIPP
• French rules value listed shares using the average of the last 30 trading prices before death, not the closing price on the day itself
• Wrapping shares in a UK ISA changes nothing for French succession tax — the ISA wrapper has no legal existence in France
• If you're UK-connected, your estate can face this tax twice: France taxes your heirs on what they receive, and the UK's own inheritance tax can still apply to the same assets depending on your UK residence history

A share portfolio sitting quietly in a UK dealing account doesn't feel like the kind of thing anyone plans around. Assurance-vie gets the spotlight in French estate planning, SIPPs get their own tax treatment, and shares just get left where they are. The problem — shares left where they are get taxed the hard way.

If you haven't already read how the overall French succession tax system works — the per-heir rates, the forced heirship rules, the €100,000 child allowance — start with our guide to how inheritance tax works in France first. This article assumes you already know that background and focuses specifically on where shares and investment portfolios fit into it.

Shares get no special treatment — that's the whole point

It's just an asset in your estate, taxed exactly the same way as cash in a bank account would be.

That means the standard per-heir rates apply in full: 0% for a spouse or PACS partner, a €100,000 allowance per child with rates from 5% up to 45% above it, and far smaller allowances for anyone more distantly related. There's no separate "investment portfolio" category, no reduced rate, and no extra allowance for holding wealth in shares rather than cash.

If you're weighing whether to leave a portfolio as shares or move the money into assurance-vie or another structure before you die, this is the comparison that matters — see the worked example in our main inheritance tax guide, where the same €200,000 left via ordinary means versus assurance-vie produces a dramatically different tax bill.

How French rules actually value your shares

You'd assume the value used is whatever the shares were worth on the day someone died — the closing price on that date. French law works differently.

For shares and securities listed on a regulated market, France values them using the average of the last 30 trading prices before the date of death, under Article 750 ter and the valuation rules that follow it in the Code général des impôts. Each daily price used is itself an average of the day's high and low, not just the closing tick. This applies to foreign securities too — a UK-listed share is valued off its own exchange's prices, not converted through a Paris listing that doesn't exist for it.

Two consequences follow directly from this:

• A single bad or good day near the date of death doesn't set the tax bill. If markets spiked or crashed the day someone died, the 30-day average smooths that out — for better or worse, depending on which direction the market moved.
• If the shares aren't listed at all — an unlisted company, a fund with no public quotation — the 30-day average rule doesn't apply. Heirs have to file an estimated declaration of value instead, based on the best available evidence, and the tax office can challenge that estimate later using comparable prices from around the same date.

For fund holdings — a SICAV or an FCP (the French equivalents of an open-ended fund) — French rules use the last known redemption value at the date of death rather than the 30-day average. If your portfolio holds UK unit trusts or OEICs, the equivalent principle applies: the fund's own published price at the relevant date, not a 30-day smoothing.

Whichever value applies, it's the GBP value converted to euros at the exchange rate on the date of death that goes into the succession declaration — the same currency-conversion mechanic that applies to every foreign asset in a French estate.

Does an ISA wrapper change anything here?

No.

An ISA is a UK tax-law construct. It has no legal existence in France at all — not for income tax, and not for succession tax either. If you've read our guide to how ISAs and SIPPs are taxed in France, you already know that ISA income and gains are fully taxable in France while you're alive, exactly as if the ISA wrapper didn't exist. The same logic carries through to death: shares held inside a Stocks and Shares ISA are valued and taxed for French succession purposes exactly like shares held in an ordinary dealing account, because as far as French law is concerned, there's no meaningful difference between the two.

The only place the ISA wrapper still matters is on the UK side — for UK tax purposes, while the account holder was alive, and for UK inheritance tax, which is a separate system covered below.

The UK side: your estate can be taxed twice

Here's the part that catches long-term UK expats off guard in the other direction. Moving to France and becoming a French tax resident doesn't automatically take your worldwide assets out of the UK inheritance tax net.

Until 6 April 2025, this depended on a concept called domicile — a UK legal idea, separate from tax residence, that could keep someone "UK domiciled" for inheritance tax purposes for years after they'd left. From 6 April 2025, the UK replaced this with a residence-based test. You're now a long-term resident (LTR) for UK inheritance tax if you've been UK tax resident for at least 10 of the previous 20 tax years — and if you are an LTR, the UK can tax your worldwide estate, shares in France included, regardless of where you now live.

The practical effect for someone who's built a life in France:

• If you've been out of the UK long enough, you may no longer be an LTR — and your worldwide assets, including your French-held shares, fall outside UK inheritance tax scope entirely.
• If you left more recently, there's a tail. Someone who was UK resident for a long time before leaving can remain within UK inheritance tax scope on worldwide assets for up to 10 years after leaving, depending on exactly how long they were UK resident beforehand.

This means the same share portfolio can, in principle, be assessed by both countries — France taxing your heirs on what they receive under the rates above, and the UK separately taxing the value of your worldwide estate if you're still within the LTR tail. The UK-France double tax treaty on inheritance provides relief mechanisms for this overlap, but working out exactly where you stand depends on your specific UK residence history — this is genuinely worth a conversation with a cross-border estate planning specialist rather than assuming either side automatically doesn't apply.

Where People Lose Money on This

The mistake isn't holding shares — it's assuming that because SIPPs and assurance-vie get special mentions in French estate-planning, an ordinary share portfolio must have some similar treatment too. It doesn't. A €300,000 share portfolio left to a niece is taxed exactly as harshly as €300,000 in cash would be — a €7,967 allowance, then 55% on the rest. The tools that reduce that bill (assurance-vie, lifetime gifting, usufruct structuring) all exist — see our main inheritance tax guide for how they work — but none of them apply automatically just because the underlying asset happens to be shares rather than cash.

Common Mistakes

1. Assuming an ISA wrapper protects shares from French succession tax. It doesn't. France doesn't recognise the ISA wrapper for any purpose, income tax or succession tax — shares inside an ISA are valued and taxed exactly like shares in an ordinary account.

2. Valuing shares at the date-of-death closing price instead of the 30-day average. This is a genuine, specific French valuation rule that differs from what most people assume, and it can materially change the taxable value declared.

3. Assuming leaving the UK automatically removes UK inheritance tax exposure. The old domicile rules are gone, replaced by the long-term resident test from 6 April 2025 — but the LTR tail can keep worldwide assets in UK IHT scope for years after someone has moved to France.

4. Not distinguishing a SIPP from an ordinary share account. A SIPP has its own UK-side pension tax treatment on drawdown, entirely separate from succession tax — see our ISAs and SIPPs guide and SIPPs vs Assurance Vie comparison. A plain share dealing account has none of that separate treatment — it's a normal estate asset from day one.

5. Treating unlisted or fund holdings the same as listed shares. The 30-day average rule only applies to securities on a regulated market. Unlisted shares need an estimated declaration; SICAV/FCP-style funds use their last published redemption value instead.

Frequently Asked Questions

Is a UK share dealing account taxed the same as cash for French inheritance tax?

Yes. A personal share dealing account or General Investment Account is an ordinary estate asset, taxed under the standard per-heir rates — 0% for a spouse, a €100,000 allowance per child with rates up to 45% above it, and smaller allowances further down the family tree. There's no separate category or reduced rate for holding wealth in shares rather than cash.

How are shares valued for French inheritance tax if the person died on a day the market moved sharply?

French rules use the average of the last 30 trading prices before the date of death, not the single closing price on that day. This smooths out short-term volatility around the date of death, for listed securities on a regulated market.

Does it matter that my shares are inside a Stocks and Shares ISA?

No. France doesn't recognise the ISA wrapper for any purpose. Shares inside an ISA are valued and taxed for French succession tax exactly as they would be in an ordinary dealing account.

Can both France and the UK tax the same investment portfolio when I die?

Potentially, yes. France taxes what each heir receives under its own succession rates. Separately, the UK can tax your worldwide estate if you're a "long-term resident" for UK inheritance tax purposes — broadly, UK tax resident for at least 10 of the previous 20 years, with a tail of up to 10 years after leaving the UK. The UK-France tax treaty provides some relief for double taxation, but the exact position depends on your specific UK residence history.

What happens if my shares aren't listed on a public exchange?

The 30-day average valuation rule only applies to securities quoted on a regulated market. For unlisted shares, your heirs file an estimated declaration of value, which the tax authority can later query using comparable prices from around the same date.

Sources: Article 750 ter, Code général des impôts (territorial scope of French succession tax) · BOI-ENR-DMTG-10-40-10-40, BOFiP (valuation of listed securities and fund units) · IHTM13061, HMRC Inheritance Tax Manual (background on the pre-2025 deemed domicile test, superseded from 6 April 2025 by the long-term residence rules)