What happens to your UK ISA when you move to Spain

UK ISAs work because UK tax law explicitly exempts income and gains inside the wrapper. The wrapper itself doesn't do anything magical — it's a tax fiction that depends on UK law granting the exemption.

Spanish tax law has no concept of an ISA. Spain looks through the wrapper at the underlying investments and taxes them as if you held them directly. UK gilts inside an ISA are treated as UK gilts. UK equity inside a Stocks & Shares ISA is treated as UK equity. The fact that they sit inside an ISA is irrelevant.

Once you're Spanish tax resident, every income event inside the ISA is taxable:

• Dividends from UK equity holdings: 19-28% Spanish savings-income tax
• Interest from cash ISAs or bond holdings: 19-28% Spanish savings-income tax
• Capital gains from sales inside the ISA: 19-28% Spanish CGT
• Distributions from ISA-held funds: 19-28%

The UK doesn't apply withholding tax on UK dividends to Spanish residents (treaty residual rate is 0% for most cases). So you get the gross dividend and pay full Spanish tax on it. No double taxation, just full Spanish exposure where you were expecting full UK exemption.

ISAs are declared in Category 2 of Modelo 720 (securities, funds, insurance with surrender value). The €50,000 threshold is tested across all Category 2 holdings combined, not per ISA.

For most British movers with multiple ISA years of contributions, the combined ISA value will exceed €50,000 in year 1 of Spanish residency, triggering full Category 2 disclosure. After that, refile only when value rises by €20,000+ across the category.

UK ISA contribution rules require you to be UK tax resident in the tax year of contribution. Once you become UK non-resident, the year you leave, you can still make ISA contributions for the days you were UK resident. After that, no new contributions.

You can keep the existing ISA holdings. You can sell and rebuy within the ISA. You just can't add new money. The ISA remains technically valid under UK law and the UK doesn't tax the income — Spain does.

The clean planning sequence for someone with significant ISA holdings:

1. Crystallise gains while UK resident. Sell positions with large unrealised gains BEFORE the move. UK ISA tax exemption shelters the gain entirely. Rebuy within the ISA or hold as cash.
2. Consider repositioning to growth (vs income) assets. Capital gains can be timed; dividends arrive on the schedule the company chooses. For Spanish tax efficiency post-move, low-yield growth holdings reduce annual income events.
3. If Beckham Law is on the table: ISAs are largely sheltered during the regime because foreign-source investment income is Spain-exempt. This makes ISA-heavy portfolios much more workable for Beckham-eligible movers.
4. If not Beckham-eligible: consider whether unwinding the ISA before move and using a Spanish-tax-efficient structure (e.g. a unit-linked life bond under Spanish rules) makes sense. Run the numbers carefully.
5. Don't forget Modelo 720 if combined securities exceed €50k.

Under Beckham Law, foreign-source investment income is largely NOT taxable in Spain during the 6-year regime. UK ISA income is foreign-source from the Spanish perspective. So ISA dividends, interest and (in most interpretations) capital gains are Spain-exempt during Beckham.

Modelo 720 is also waived under Beckham. So the ISA effectively continues to function as a tax-efficient wrapper for Beckham-eligible movers, at least within Spain.

At regime exit (end of year 6), Spanish tax treatment of the ISA kicks in fully. The pre-exit planning then matters again — see the planning section above.