| UK | allows dual citizenship, nothing to apply for |
| Your home country | decides whether you keep your nationality when you naturalise |
| Consular help | none from Britain in your other country of citizenship |
| Travel | British dual nationals cannot get an ETA |
| Children | British citizenship passes to children born abroad for one generation |
| As of | November 2026 |
The British side
GOV.UK puts it briefly: dual citizenship is allowed in the UK. You do not need to apply for it, and British citizens who take another nationality stay British. Two practical consequences are worth knowing. In your other country of citizenship, Britain gives you no consular help. And as a British dual national you cannot get an ETA; you travel to the UK on your British passport or with a certificate of entitlement.
How to become British in the first place is explained on our page on British citizenship.
Your home country decides
Across Europe the answers differ widely. Many countries now accept dual citizenship without conditions. Some still treat voluntarily taking another nationality as giving up their own, so you lose it automatically on the day you become British. Others let you keep it only if you applied for, and were granted, permission before you naturalise. A few allow it for some groups and not for others, for example depending on where you live or how you acquired the second nationality.
Rules also change. Several countries have relaxed their position in recent years, and Brexit itself changed the picture for some, because naturalising in an EU member state was sometimes treated differently from naturalising in a country outside the EU. So the answer that applied to a friend who naturalised ten years ago may not be the answer for you today.
The only reliable source is your own country: its nationality authority, its ministry of the interior or foreign affairs, or its embassy in London. Check your own country's rules before you apply, and keep the answer in writing.
Questions to put to your home country before you naturalise
- Do I lose my nationality if I voluntarily acquire British citizenship?
- If so, can I apply to keep it, and must that permission be granted before I become British?
- Does it matter that I live in the UK, or how long I have lived abroad?
- Do I need to tell the authorities once I am British, and what happens to my passport and identity card?
- If I lost my nationality in the past, is there a way back, and on what conditions?
- What applies to my children, especially if they hold both nationalities from birth?
If you naturalised years ago
If you became British some time ago, it is worth checking that you still hold your home nationality before you next renew your home passport. Where a country's rules were stricter at the time you naturalised, you may have lost it then, even if the rules are more relaxed today. Changes in nationality law are often not retroactive. The authority that issues your passport can confirm your position.
EU and EEA citizens: the residence side
For EU citizens in the UK the British side has one more detail. According to GOV.UK, the special route to naturalisation with pre-settled status is open to citizens of the EU, Norway, Iceland and Liechtenstein, but not to Swiss citizens. And Swiss citizens with settled status lose it after four years in a row outside the UK, rather than the five years that apply to others. How the status works is explained on our page on the EU Settlement Scheme.
Children with two nationalities
Children of a British parent and a parent from another European country often acquire both nationalities at birth. On the British side this turns on the rules for descent: citizenship normally passes to children born abroad for one generation only. If the British parent is British only by descent, the child usually needs to be registered. We explain this in the section on descent. Whether the child also holds the other parent's nationality, and keeps it as an adult, is again a question for that country's law.
Two passports, one tax position
Nationality does not decide income tax, in the UK or in most of Europe. What counts is where you live and where you are tax resident. More in status and tax and in our overview of the UK tax system.
We advise on the order of steps, the timing and the tax consequences.
Frequently asked questions
Will I lose my nationality if I become British?
Not because of anything the UK does. It depends entirely on your home country's law. Some countries allow dual citizenship, some take their nationality away, some need permission first. Ask your own country before you apply.
My child has a British parent and a parent from another European country. Does the child have both nationalities?
If the child acquired both at birth, usually yes. Whether the child is British depends on the British rules for descent; the other nationality depends on the other country's law.
Do I have to register dual citizenship in the UK?
No. There is nothing to apply for in the UK.
Sources: GOV.UK: Dual citizenship; GOV.UK: Apply for citizenship if you have indefinite leave to remain; GOV.UK: Apply to the EU Settlement Scheme
