Dual citizenship

It is my understanding that due to new rule he would have to enter UK on a UK passport and does not need an ETA. He could then fly back to US using US passport.

Yes he does

Tinka is correct - because he is a British citizen he needs to enter the UK using a British passport. Alternatively he can travel using a US passport and a digital Certificate of Entitlement to Right of Abode (which is what I have linked to my non British passport), but this is more expensive than a British passport.

He does not need an ETA.

Getting a British passport is pretty quick and can all be done online.

Thanks everybody for your replies. We did not even realize that he was still considered a UK citizen until this past week. We thought his UK citizenship was relinquished when he became a US citizen 50+ years ago per the US naturalization oath. Surprise. Somehow he was issued an ETA by the UK government. I can’t even remember if they ask where you were born on that application as we both applied months ago. But certainly his US passport lists his place of birth in the UK. I guess we need to get busy tomorrow getting him a UK passport.

Does the UK ETA not ask about 'any other citizenship' in the application process? I am surprised he was able to get an ETA
( my travels have not included the UK, so I have no idea what questions are included in the ETA application process)

Why are you changing passport rules for dual citizens?
The UK is moving to a modernised ‘digital permission’ system where international carriers are required to confirm, through automated checks against Home Office records, that passengers have valid permission or status to travel to the UK. All carriers (e.g. airlines, maritime and rail) have now been equipped with the necessary tools to verify travel permission via automated digital checks with the Home Office.
We recognise that this is a significant change for carriers and travellers, but we have been clear on requirements for dual British citizens to travel with a valid British passport or Certificate of Entitlement, in line with those for all British citizens.
Public information strongly advising dual citizens to travel with a valid UK passport or Certificate of Entitlement has been available since October 2024, including official guidance on GOV.UK.
https://homeofficemedia.blog.gov.uk/electronic-travel-authorisation-eta-factsheet-april-2026/

Hi Joe,

We applied for the ETA’s a few months ago so I don’t recall what was asked for on the application but we would have answered honestly. We had no idea that he was still a UK citizen until a few days ago. A lot of naturalized American citizens will probably be in the same predicament being unaware of their dual status. We were surprised to learn that our daughter who was born here in the US also has dual citizenship by descent.

"Does the UK ETA not ask about 'any other citizenship' in the application process? I am surprised he was able to get an ETA"

The system asks your nationality, and I'm assuming he then chose 'United States', as he didn't realise he was still a British citizen. There are many, many people who don't realise - either they think they lost it when they naturalised as a citizen of a foreign country, or they don't realise they obtained by descent from a parent who was a British citizen at their birth.

OP - it doesn't matter what his place of birth is, just his current citizenship status. You can be born in the UK and not a British citizen, and vice versa.

Simon,
My husband was born in the UK and his parents were both British citizens so he is definitely a dual citizen. His British ancestry goes way, way back. He is distantly related by dna per Ancestry.com to a Neolithic? man called Cheddar Man whose remains were found in a cave in Cheddar Gorge. Cheddar Man’s remains are in the Natural History Museum in London I believe so we will have to make a visit and pay our respects to his ancestor when we are there (assuming the remains can be viewed). So his UK roots run deep.

The only reliable answer to your question needs to come from the UK Embassy. Tax Treaties among other things now make this kind of thing rather important. The US started a lot of it and other countries are keeping up (I will forgo commenting on whether the initial decisions on all sides were a good idea). For example, if you are a naturalized US citizen and then move back to your home country you still have to file US Income Tax Forms (even if you owe nothing!!!). Fortunately a lot of this bumph can be handled online these days.

What everyone says here is correct. All UK ciitzens must enter the UK on their UK passport. Note that the US has had this same rule for quite some time (which means dual UK/US citizens must bring both passports when travelling between these two countries). A few things to add:

-There was a time in the US when naturalised citizens had to renounce their other citizenship(s) (earlier in the 20th C) but that is no longer the case.
-Some countries do not allow dual citizenship (Spain and India are two I can think of) so obtaining a new citizenship means you have to renounce. However the UK and US both allow for dual citizenship at this time.
-I would check whether your daughter is "automatically" a UK citizen or she is just eligible for UK citizenship. It doesn't sound like she ever claimed it, in which case she would not need to worry about applying for a passport.

I think most of us here originate from Cheddar Gorge Man! If you visit the Gorge itself in Somerset, they have a replica skeleton in the bit of the caves where they found him.

Rules are here
https://www.gov.uk/dual-citizenship