Does the UK Allow Dual Citizenship? 2026 Rules

Yes. The United Kingdom has permitted dual and multiple nationality without restriction since the British Nationality Act 1948, carried forward under the British Nationality Act 1981. There is no legal limit on the number of citizenships a British citizen may hold and no requirement to declare a foreign citizenship to any UK authority.

The legal basis: the British Nationality Act 1948 and 1981

The United Kingdom's permissive approach to dual nationality dates back to the British Nationality Act 1948, which removed the earlier common law doctrine that treated a British subject's voluntary acquisition of a foreign nationality as automatic loss of British status. The British Nationality Act 1981, which restructured British nationality law into the categories still used today, carried this position forward without introducing any new restriction on multiple nationality. Neither Act, nor any later amendment, sets a maximum number of citizenships a British citizen may hold, and neither requires a British citizen to choose between British nationality and a second citizenship at any point. This makes the United Kingdom considerably more permissive than a number of other countries that either prohibit dual nationality for their own citizens outright or require formal permission to retain it after naturalising elsewhere.

In practical terms, this means a British citizen who is born with, marries into, naturalises in, or otherwise acquires a second, third or further citizenship keeps British nationality automatically and simultaneously, without any application, declaration or fee payable to a UK authority. The only way a British citizen loses British nationality is through a deliberate act of renunciation, a separate formal process administered by the Home Office and covered in detail in the dedicated guide to renouncing British citizenship linked at the end of this page.

What the UK does and does not require you to do

There is no UK register of dual nationals, no requirement to inform HM Passport Office, HMRC or the Home Office that a foreign citizenship has been acquired, and no requirement to surrender or annotate a British passport as a result. A British citizen travelling on a foreign passport when entering or leaving a country that recognises that other nationality is acting entirely lawfully from a UK perspective; the only practical constraint on this front is that, since the ETA changes covered in HM Passport Office's 2026 guidance, British citizens travelling to the UK generally need to present a valid British passport or Certificate of Entitlement, since British nationals cannot use the UK's Electronic Travel Authorisation scheme, which is designed for non-British travellers.

Where UK law does engage with a second citizenship is indirectly, through tax and reporting obligations that arise from residence, income or assets rather than from nationality itself. Holding a second citizenship, on its own, triggers no UK tax consequence; what matters for HMRC is where the individual is tax resident and domiciled, questions covered in the dedicated guide to UK tax residence when working abroad linked below.

Which other countries restrict dual nationality, and why that matters

Because the UK side of the equation places no restriction on dual nationality, any limitation a British citizen encounters when acquiring a second citizenship comes entirely from the laws of the country granting that second citizenship, not from the United Kingdom. Some countries require a naturalising citizen to formally renounce their prior nationality as a condition of naturalisation, while others permit dual nationality for citizens by descent or birth but not for those who naturalise as adults, and a smaller number restrict dual nationality altogether regardless of how it was acquired. These rules vary significantly by country and change periodically, so a British citizen considering a second citizenship needs to check the specific requirements of that country's naturalisation law directly, since UK guidance cannot confirm what another sovereign state will or will not permit.

None of the citizenship-by-investment programmes covered elsewhere on this site, including Grenada, Dominica, St Kitts and Nevis, Antigua and Barbuda, St Lucia, Malta, Turkey or Vanuatu, require the applicant to renounce any existing citizenship as a condition of the programme; all operate on a dual-nationality basis, which is part of why these routes are widely used by nationals of countries, including the UK, that themselves permit multiple nationality freely.

Consular protection limits for dual nationals

One genuine limitation dual nationals face has nothing to do with whether the UK recognises the second citizenship, and everything to do with international law around consular access. When a British and other dual national is physically present in their other country of nationality, that country is generally entitled under international law to treat the person as solely its own national for the purposes of consular access, meaning the Foreign, Commonwealth and Development Office may have limited or no ability to provide consular assistance while the person is inside that other country. This is not a UK legal restriction on dual nationality itself; it is a practical constraint on the UK's diplomatic reach inside another sovereign state, and it applies regardless of how strongly the person identifies as British. Dual nationals travelling to or living in their other country of nationality should factor this into their planning, particularly around legal difficulties or detention, where the assumption that British consular support will be available in the same way it would be in a third country does not reliably hold.

Frequently asked questions

Do I need to tell the Home Office if I get a second citizenship?

No. There is no requirement to declare, register or report acquiring a foreign citizenship to the Home Office, HM Passport Office or any other UK authority. British nationality continues automatically alongside the new citizenship unless it is deliberately renounced.

Will I lose my British citizenship if I become a citizen of another country?

No. Since the British Nationality Act 1948, voluntarily acquiring a foreign citizenship does not cause automatic loss of British nationality. British citizenship is only lost through a deliberate, formal renunciation process.

Can the UK refuse to recognise my second citizenship?

The UK does not need to recognise a second citizenship for it to be valid; recognition is a matter for the country granting it. The UK simply does not restrict British citizens from holding it, regardless of how many other nationalities they acquire.

Does dual nationality affect my UK tax position?

Not directly. UK tax liability depends on residence and domicile status, assessed under the Statutory Residence Test and related rules, rather than on how many citizenships a person holds. Holding a second citizenship on its own creates no UK tax consequence.

Can the UK help me if I'm in trouble in my other country of nationality?

It may be limited. When a dual national is physically present in their other country of citizenship, that country can generally treat the person solely as its own national, which can restrict the level of consular assistance the Foreign, Commonwealth and Development Office is able to provide.