UK ISA and Premium Bonds When Moving to Portugal: Britons

GOV.UK says you cannot pay into a UK ISA once you are a non-UK resident, but you can keep it and it keeps its UK tax relief. NS&I says Premium Bonds need a UK bank or building society account in your name and a check of the local rules where you live.

This guide is written mainly for Britons. It sits under the guide to opening a bank account in Portugal and takes up one question from the guide on keeping US or UK bank accounts in Portugal: what happens to the UK savings products you already hold. Americans’ equivalent questions, for U.S. accounts and filings, are in the U.S. articles, starting with U.S. taxes for Americans living in Portugal. This is not tax or financial advice. It says what each page says on the day we read it.

What the pages say, and when

We read the pages on 19 October 2026. The GOV.UK ISA guide gives the maximum you can save in ISAs for the 2026 to 2027 tax year, which began on 6 April 2026; that is the latest dated figure behind this guide, so 6 April 2026 is the date of its information. The GOV.UK guides on savings interest and on UK income for people living abroad carry no date we could read on the page. The NS&I pages show a copyright line of 2026 and no update date. The HMRC page on Automatic Exchange of Information was last updated on 31 December 2020, when the Brexit transition period ended.

We did not read any page of the Portuguese tax authority on ISAs or Premium Bonds. Where the guide would need one, it says so.

Can I still pay into my ISA once I live in Portugal?

No, according to GOV.UK. The page says that if you open an ISA in the UK, move abroad and become a non-UK resident, you cannot put money into it, “unless you’re a Crown employee working overseas or their spouse or civil partner”. The same page sets who can open an ISA: you must be 18 or over, and either resident in the UK or a member of the armed forces or a Crown servant (for example diplomatic or overseas Civil Service), or their spouse or civil partner if you do not live in the UK.

GOV.UK adds that:

• You must tell your ISA provider as soon as you stop being a UK resident.
• You can keep your ISA open and you still get UK tax relief on the money and investments in it.
• You can transfer an ISA to another provider even if you are not resident in the UK.
• You can pay into your ISA again if you return and become a UK resident, subject to the annual ISA allowance.

For the residence test itself, GOV.UK points to its UK residence and tax guidance, and our guide on how HMRC treats your UK residence when you move to Portugal covers what we read there.

Is the interest in my ISA taxed?

In the UK, GOV.UK says you do not pay tax on interest on cash in an ISA, or on income or capital gains from investments in an ISA, and that if you complete a tax return you do not need to declare any ISA interest, income or capital gains on it. NS&I says the same of its Direct ISA: the interest is free from UK Income Tax, so you do not need to declare it to HMRC.

That is the UK side only. NS&I’s page on living abroad adds a warning that applies to any UK product: some NS&I accounts “might be liable for local tax” in the country you live in, and you should check the local laws and regulations there. None of the pages we read says how Portugal taxes an ISA, or whether it treats it as a tax-free wrapper at all. We did not find that on a page of the Portuguese tax authority, so we do not state it. If you become a Portuguese tax resident, see our guide to Portuguese tax residence and ask a Portuguese tax adviser about your ISA before you file. If you arrive under the special regime for new residents, the IFICI guide covers what we read about it; it does not say anything about ISAs.

What does NS&I say about Premium Bonds when I live abroad?

NS&I’s page “Saving with us when living abroad” says it has always been a UK savings provider, backed by HM Treasury, with some customers who live outside the UK. For Premium Bonds it says:

The page does not mention Portugal, and we did not read a Portuguese page saying whether holding Premium Bonds is allowed or how prizes are taxed there. That is a question for NS&I and for a Portuguese adviser, not something we can answer. NS&I says only that “tax-free” means exempt from UK Income Tax and Capital Gains Tax.

What if my UK bank account is closed?

This matters because NS&I ties every product to a UK account. It says that to save with it you need a UK bank or building society account in your name, because it can only make payments to, and receive payments from, a UK account in pounds sterling. Its Customer Agreement requires you to keep such an account open to operate an NS&I account. If your bank closes your account and you cannot give details of another UK bank or building society account, you can no longer hold an NS&I account, cannot make further deposits or open new accounts. NS&I says its only alternative is then a warrant, like a cheque, which could be costly to deposit into a non-UK bank account.

NS&I’s page speaks of banks that told customers in EU countries they could no longer keep a UK account after the Brexit transition period, and recommends that you check with your bank whether it intends to close yours. If it does, you tell NS&I the details of another UK account that can take BACS payments. Whether your own bank will keep your account is the bank’s decision; see keeping US or UK bank accounts in Portugal and sending money between Portugal and the UK.

Do I pay tax on other UK savings interest, and what is the Personal Savings Allowance?

GOV.UK’s guide to tax on your UK income if you live abroad says you usually have to pay tax on your UK income even if you are not a UK resident, and lists savings interest among the examples. It says:

• You usually have to send a Self Assessment tax return if you live abroad and have taxable savings interest from UK banks or building societies.
• You do not need to report income to HMRC if you have already claimed tax relief under a double-taxation agreement.
• Income Tax is no longer automatically taken from interest on savings and investments.
• Non-residents cannot use HMRC’s online services to report; they send a Self Assessment return with an SA109 form by post, use commercial software that supports SA109, or use a tax professional.
• You get a Personal Allowance of tax-free UK income if you are a British citizen, an EEA citizen or have worked for the UK government that tax year (it adds that you might also get it if the double-taxation agreement between the UK and the country you live in includes it), and if you are not a UK resident you claim it with form R43 at the end of each tax year in which you have UK income.

The GOV.UK guide to tax on savings interest sets the Personal Savings Allowance: up to 1,000 pounds of interest tax-free for a basic rate taxpayer, 500 pounds for a higher rate taxpayer and 0 for an additional rate taxpayer. The same page says banks and building societies tell HMRC after 5 April each year about the interest they paid. The pages we read do not say how the Personal Savings Allowance applies to a non-resident, so we do not say it either. NS&I says that for its taxable products, such as the Direct Saver, interest is paid without deduction of tax but is subject to UK Income Tax, and “if you’re liable for UK Income Tax” it counts towards the Personal Savings Allowance.

GOV.UK also says the country where you live might tax you on your UK income, and if it has a double-taxation agreement with the UK you can claim relief in the UK to avoid being taxed twice. For how the UK-Portugal position reads, see the guide to UK taxes and HMRC for Britons in Portugal.

Will my UK bank or NS&I tell HMRC where I live?

Two things happen, and neither is something you file.

HMRC says that under Automatic Exchange of Information agreements, financial institutions such as banks and building societies provide information on non-UK residents with financial accounts and investments in the UK to HMRC, which shares it with the relevant countries. NS&I’s page on living abroad describes the Common Reporting Standard as a global standard for automatic exchange of financial account information, and says it asks all financial institutions, including NS&I, in a participating jurisdiction to gather certain customer information and report it to local tax authorities. These pages do not list which countries receive which accounts or say what Portugal does with them.

What should I do before and after the move?

If you also receive the UK State Pension, our guide on the UK State Pension for Britons in Portugal covers paying it into a Portuguese account. The matching guide is voluntary National Insurance contributions for Britons in Portugal.

Pages read for this guide

On 19 October 2026: the GOV.UK guides Individual Savings Accounts (ISAs), Tax on savings interest, Tax on your UK income if you live abroad and Tell HMRC about a change to your personal details; the HMRC guidance Automatic Exchange of Information: introduction; and the NS&I pages Premium Bonds, Saving with us when living abroad and How to change your personal details.