Is a UK ISA taxable in France?

No official French text mentions the UK ISA (Individual Savings Account), so the general rules apply. A French resident's foreign income is taxed like French income. Under the France–UK treaty (convention fiscale), interest and capital gains are taxed by France, and so are dividends, although the UK may withhold up to 15%. That the UK's ISA exemption does not bind France is our own reading of these rules.

What the rules say

Income	Taxed, for a French resident, by	Basis	Source
Foreign income in general	Taxed in the same way as French income	BOFiP § 20	BOI-IR-BASE-10-10-10-10
UK dividends (dividendes)	France; the UK may also tax, up to 15% of the gross amount	Art. 11(1)(a), (b)	France–UK treaty
UK interest (intérêts)	France only	Art. 12(1)	France–UK treaty
Gains on property other than real estate and certain other assets (gains en capital)	Only the seller's State of residence	Art. 14(5)	France–UK treaty
The same gains, for a former UK resident	The UK may also tax if the seller was UK-resident in the year of sale or in any of the previous six tax years	Art. 14(6); BOFiP § 220	Treaty; BOI-INT-CVB-GBR-10-20

The French rule: foreign income is taxable

According to BOFiP on taxable income (revenu global), tax is charged on all the income of the members of the tax household (foyer fiscal), and any sum received is taxable unless a specific provision of law exempts it (§ 1). The origin of the income makes no difference: income from sources outside France is taxed in the same way as income arising in France (§ 20). Foreign income can be excluded only by a tax treaty or because the recipient does not live in France (§ 20, note 2).

What the France–UK treaty says

Dividends (Article 11)

Dividends arising in one State and paid to a resident of the other are taxable in the State where the recipient lives. The State where they arise may also tax them, but if the recipient is the beneficial owner (bénéficiaire effectif), that tax is capped at 15% of the gross dividend. UK tax on the dividends is credited against French tax: the credit equals the tax paid in the UK in line with the treaty, up to the amount of French tax on that income (Art. 24(3)(a)(ii)).

Interest (Article 12)

Interest arising in one State and beneficially owned by a resident of the other is taxable only in the other State. For a French resident, that means France alone.

Capital gains (Article 14)

Gains on the sale of property not listed in paragraphs 1–4 (real estate; certain shares and rights that derive most of their value from real estate; assets of a permanent establishment; ships, aircraft and rail vehicles used in international traffic) are taxable only in the seller's State of residence (para. 5). Paragraph 6 lets a State tax, under its own law, the gains of a person who was resident there in the year of sale or at any time in the six previous tax years. If the UK taxes a French resident's gain on that ground alone, it is the UK, not France, that has to relieve the double taxation (Art. 24(4)(a); BOFiP § 240 and the last paragraph of § 260).

What this article does not cover

• The ISA itself. No official text mentions it. We checked the full body of BOFiP currently in force (the bofip-vigueur dataset on data.economie.gouv.fr, 08.10.2026) and the treaty text. There is no official guidance on whether income inside an ISA counts as dividends, interest or gains.
• The exemption. The statement "the UK ISA exemption does not bind France" is not a quotation from the law. It is our own conclusion from the two rules above: French law taxes income unless a specific provision exempts it, and the treaty says nothing about the ISA.
• Reporting. The sources used here do not say which line of the return ISA income goes on, or whether the ISA has to be reported as a foreign account.

What can change the answer

• Tax residence. Everything here assumes residence in France. For someone resident in both countries, the treaty settles the question under Article 4.
• Real estate held inside. Gains on shares, interests and rights that derive most of their value from real estate may be taxed by the country where the property is located; for shares, this does not apply if they are regularly traded on a regulated market (marché réglementé) (Art. 14(2)).

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This material is for general information and does not replace individual advice.