Travelling as a UK Dual Citizen: What Passport to Use and When for Seamless International Travel

British dual citizens do not need a UK Electronic Travel Authorisation, but they must show an accepted document when travelling to the UK. Since automated permission checks became enforceable on 25 February 2026, presenting only a foreign passport can lead to extra checks or denied boarding if the carrier cannot confirm your status. A valid British passport is usually the simplest option. Our guide to travelling with two passports explains the wider approach.

What changed under the ETA system

An ETA is digital permission to travel, not permission to enter. It costs £20 and normally allows multiple journeys over 2 years, or until the linked passport expires. British and Irish citizens, including dual citizens, are exempt and cannot use an ETA to prove British status.

Carriers check passenger details electronically against Home Office records. The official position is available on GOV.UK. These checks do not alter your nationality or the UK dual citizenship rules; they change how you prove it.

Which document should you use?

Situation	Document to carry
Travelling to the UK	A valid British or Irish passport, or a Certificate of Entitlement
Entering your other country of citizenship	That country’s passport where required
Visiting a third country	The passport meeting the destination’s entry rules
Naturalised after settling under the EU Settlement Scheme	Your other valid passport or qualifying identity card, with the EUSS record linked
British passport expired	It may be accepted with an ETA-eligible foreign passport, at the carrier’s discretion

A digital Certificate of Entitlement proves the right of abode for someone travelling on a foreign passport. The fee is £589. Certificates granted from 26 February 2026 do not expire, but the current foreign passport must remain linked to the holder’s UKVI account.

Exceptions that may help

If you obtained British citizenship after settling under the EU Settlement Scheme, current guidance allows travel using your other valid passport or a qualifying EEA or Swiss identity card. Check your eVisa and update your UKVI account if the document has changed. This does not apply to every British dual national. Brexit’s ongoing effect on dual citizens therefore depends partly on how citizenship was obtained.

A carrier may accept an expired British passport issued in 1989 or later with a valid passport from an ETA-eligible nationality if the personal details match. This is discretionary and should not replace renewal.

The European side of the journey

The EU Entry/Exit System became fully operational on 10 April 2026. It records eligible non-EU short-stay travellers’ entries, exits, facial images and fingerprints. Details are available on the European Commission site. British-EU dual citizens using their EU passport are generally exempt.

ETIAS is not yet operating. The official timetable expects it in the final quarter of 2026, with the exact date to be announced. Do not apply through unofficial websites before the system opens.

Avoiding common problems

Carry both passports and ensure the names and biographical details are consistent. Use the document that meets the destination’s rules, and make sure each child has the correct document.

UK consular help is normally unavailable while you are in the other country whose citizenship you hold. Our guides to the legal perks and pitfalls of dual citizenship, tax implications for dual citizens and the pros and cons of dual citizenship explain wider issues. The UK generally allows you to keep your British citizenship when acquiring another nationality, but the other country may not.

Where parents are separated, our child custody solicitors can advise on consent for travel, while our family law solicitors can help with wider arrangements. A lasting power of attorney can support affairs at home during long absences, and our conveyancing solicitors can assist with property matters.

Frequently asked questions

Do dual citizens need a UK ETA?

No. British and Irish dual citizens are exempt.

Which passport should I use to enter the UK?

Use a valid British or Irish passport, or a foreign passport linked to a Certificate of Entitlement. The EUSS exception may apply where you settled before naturalising.

Is it legal to carry 2 passports?

Yes. The UK permits dual nationality, subject to the other country’s rules.

Sort your documents before booking

Check your documents before paying for travel, especially if your British passport has expired or your UKVI account needs updating. Athi Law can advise on nationality status, travel documents and holding more than one citizenship.