It can lead to complications.
Arrive at Heathrow and use my British passport (born there) to skip the lines.
But I am departing for another country with its business visa in my US passport (I live/work in the USA)
They check my US passport to confirm the entry visa for destination but can’t find a UK entry stamp. Look at me (I’m very white and nerdy) and ask “dual citizen? – “happens all the time, no problem”
I am a British subject with the right of abode. I had a British passport for a long time but stopped renewing it. I am also a Canadian citizen with a Canadian passport. When I enter Britain, about half the time the customs officer asks me if I am British (coming to a country to visit your sister, for example, will get you asked that) and when I say “well, I was born here”, they say “why are you travelling on a Canadian passport?” (which also includes a line saying where I was born.) This is usually a reasonably glary moment that could possibly make you feel the interview was not going well, but I know they have no choice and have to let me in. I say that I’ve lived in Canada since 1969 and that it got to be too much effort to renew my British passport. Then they let me in.
Disclaimer: I never have any problems with border guys and then someone else comes after me with the exact same situation and has a problem. I’m extremely lucky. I can’t guarantee you’ll have as easy a time as me. But this is what I do.
Firstly keep in mind that the answer to this question will vary significantly depending on the countries involved.
Some countries (eg, the US) have requirements that if you are a citizen you MUST enter using the passport of that country. So as a US/UK citizen you must always use your US passport when entering the US.
The UK does NOT have such a requirement. ie, you can enter the country using either your US or UK passports – as long as the passport you use is valid for the type of trip. eg, if you were planning to be in the UK for the next year, then you could not enter on your US passport, as a US citizen can not legally stay in the UK for that long without a visa.
Where this gets messy is what your status is within the UK if you enter using a foreign passport. It could be claimed that you are in the UK as a visiting US citizen, and thus benefits such as government health care/etc might not be available to you. Realistically the probability of this being an issue are low, but possible…
If you hold more than one passport, you’re supposed to only be consistent with what you do in a country. So enter on one, leave on the other is a no-no, but you’re fully entitled – as a US Citizen, to visit the UK.
I did the same when visiting South Africa – my friends were in the ‘tourist’ queue, and I had both passports with me, but went through the foreigner queue with them rather than use my SA one, purely because it was simpler. I asked the ticket counter when I was leaving whether it would mean I had to do anything different, and she said as well that it happens a lot, and that you just need to be consistent.
Otherwise if you use one to get in and one to get out, for example, their system could show that the US version of you overstayed – and nobody wants that 🙂
EDIT
This forum and others point out anecdotal experiences where they or a family member with both citizenships have had no problems. The UK (unlike the US to some extent) is fine with dual citizenship, especially given the scope of the Commonwealth.
However, just a thought, you should realise you’d likely be bound by the law of entering as a foreigner, and possibly not have recourse to public funds, for example – although that part I’m not totally certain on – not a lawyer 😉
Credit:stackoverflow.com‘