Travelling on two passports: an essential guide for UK dual citizens

As a UK dual citizen, you can legally hold and travel with more than one passport. The practical rule is simple. Use a valid British passport, Irish passport or Certificate of Entitlement when travelling to the UK, and use your other passport where that country requires or expects its own citizens to enter as nationals.

Since the UK’s Electronic Travel Authorisation system has moved into full enforcement, this matters more than before. British and Irish citizens, including dual citizens, do not need a UK ETA. However, you still need to prove your British or Irish status to the carrier before travel. If you only present a foreign passport and cannot show the right document, you may face boarding problems.

If you are new to holding 2 nationalities, the overview on travelling as a UK dual citizen is a useful companion piece.

Which passport to use, and when

The UK allows dual nationality. You do not have to choose between British citizenship and another nationality, although the other country’s rules should always be checked.

When travelling to the UK, GOV.UK says dual nationals can use a valid UK passport, a valid Irish passport or a Certificate of Entitlement. You can read the official guidance on travelling to the UK as a dual citizen.

For the country of your second nationality, use that country’s passport if its rules require citizens to do so. A British-Italian traveller, for example, would normally use the British passport for the UK leg and the Italian passport for Italy.

For a third country where you are not a citizen, choose the passport that gives the easier entry. If one nationality gives visa-free access and the other does not, use the more practical passport. If you are still weighing up the wider picture, the pros and cons of dual citizenship are worth a read, as is this plain English guide to UK dual citizenship.

The new border systems you need to know

Border systems have changed quickly. The EU Entry/Exit System, known as EES, became fully operational on 10 April 2026. It replaces manual passport stamping with digital records of entry, exit and refusal of entry for non-EU nationals visiting for short stays. It also records a facial image, fingerprints and travel document data. You can read the official EU update on the Entry/Exit System.

The European Travel Information and Authorisation System, or ETIAS, is expected to start in the last quarter of 2026. It will cost €20 for most applicants and will apply to visa-exempt visitors travelling to participating European countries. You can check the official ETIAS guidance.

If you hold an EU or Schengen-country passport, travel on that passport for European trips. You are not travelling as a non-EU visitor, so EES and ETIAS should not apply in the same way. If you travel on your British passport, you are treated as a non-EU visitor and the short-stay rules apply.

System	Who it affects	What dual citizens should know
UK ETA, £20	Visa-free visitors to the UK	British and Irish citizens, including dual citizens, are exempt
EU EES	Non-EU short-stay visitors to Schengen countries	Use an EU passport if you hold one
EU ETIAS, €20	Visa-exempt visitors to Europe	Expected in late 2026, EU passport holders are exempt

Risks and how to avoid them

The most common problem is being stopped before the journey starts. Airlines and other carriers check whether passengers can lawfully travel. Carry both passports, keep them valid, and present the passport that matches the country you are entering.

Keep your details consistent. If your name differs across your 2 passports, perhaps after marriage, sort it out before travel. Mismatched names can cause delays and awkward questions. Check validity rules too. For Schengen travel, British passports normally need at least 3 months left after your planned departure and must usually have been issued less than 10 years before entry.

There are longer-term consequences to understand as well. Some people worry about losing dual citizenship or whether they could be deported or stripped of citizenship. These outcomes are rare and usually tied to serious circumstances, but they are worth understanding.

Special situations to plan for

Some countries impose military service obligations on their citizens, and arriving on that passport may make the issue harder to avoid. Tax is another point, since nationality and residence can interact in complex ways. Our note on the tax implications of dual citizenship explains the basics. Brexit also reshaped travel for many families, and its ongoing impact on dual citizens still appears at borders.

Families should make sure each child has the correct passport in their own name. The rules on dual citizenship for children are not always obvious. Where parents are separated, child custody solicitors in Sheffield can advise on consent for international travel.

Frequently asked questions

Can I travel on two passports at once?

Yes. Carry both, then present the passport that fits the country you are entering.

Do dual British citizens need a UK ETA?

No. British and Irish citizens, including dual citizens, are exempt. You should travel with a valid British passport, Irish passport or Certificate of Entitlement.

Will I need ETIAS if I have an EU passport?

No, if you travel on your EU passport. ETIAS applies to visa-exempt non-EU visitors.

Is it illegal to hold two passports in the UK?

No. The UK permits dual nationality. You can normally keep your British citizenship when you take another nationality, subject to the other country’s rules.

Speak to an immigration solicitor

Travelling on 2 passports is usually simple once you know the pattern, but the detail rewards care. If you are unsure which document to use, or you are applying for a second nationality, the immigration solicitors at Athi Law can give you clear, practical guidance. We also help with partner visa matters and wider family law questions, support businesses through the employer sponsor licence process, and offer tailored legal advice for more complex cases.