We'll be arriving on Eurostar on Dec. 22nd. I'm about to apply for them. My DH and DS definitely need them. From the guidelines I shouldn't need one for reasons that aren't terribly complicated but that I don't want to post on a public forum. Should I get one anyway on general principles? Will it look weird? Will it look weirder that I don't need one and husband and son do? I'm assuming that I can apply since I'm a US citizen with a US passport. We also have plane tickets departing from the UK back to Philadelphia on the 27th. Am I overthinking this?

If you have the right of abode in the UK you don't need one afaik. When you apply they ask about second passports I believe.

My sons have UK passports, their partners and kids have EU passports so need an ETA. They have not had a problem entering and exiting the UK together.
We plan on using our UK passports to go to the UK (and from) and our EU passports to get back into the EU.

Thank you, that's good to know!

Lots of families with different passports travel together. For instance, I have a US passport, my daughter and granddaughter a British passport, and my SIL Italian and South African passports. When we travel together the only problem is deciding which line in passport control we should each queue in. Usually they allow families to stay together.

Also good to know. It did occur to me that this is the kind of thing that seems a little weird to Americans but probably isn't actually, especially in Europe. Thanks!

I advise you to look at the application and see if there is a box you can tick that covers whatever your situation is.

Mr T, born in the UK but travelling as usual on his Canadian passport, needed an ETA. There were no boxes that described him.

I am planning a trip to London in April 2026 with my spouse. Can I do both of our applications with the same email address, if they ask for one? Do you give both passport information? How long does it take to get accepted? Thanks

Where from?

I would estimate that from when I got an immediate email indicating my application was being processed to when I got the “approved” email was about 3 seconds.

From USA

You have to do individual applications as far as passport details are concerned.
It is all explained on the website.

Yes, you can both use your shared email address.
You will each be asked for passport info.
It’s a very easy process.

We are back, happy to report no issues. Very straightforward.

Topping this thread - from tomorrow dual nationals with UK nationality must have and show their UK passport to (re)enter the UK, or they need to spend an extortionate 589 GBP for a "certificate of entitlement" linked to their foreign passport, which needs renewing when the passport is renewed, and takes up to 8 weeks to get.
I believe an expired British Passport is also accepted but you would need to check on that.

You have been warned!

UK government is scrambling to soften the blow. Indeed it is not possible for dual citizens to get an ETA now, but
- at your airline’s discretion, an expired UK passport plus your other passport with an exact matching name can be accepted
- the certificate of entitlement will become digital and will transfer to your future other-country passport as you renew that one, without another £500+ charge,
https://www.gov.uk/dual-citizenship

Some people have been unaware they are considered dual citizens and therefore now need a British passport to enter Britain. If either of your parents were born in Britain, it's probable you are automatically a British citizen (by descent), as well as a citizen of whichever country you were born in or live in.

My grandsons are Dutch, even though they have a British father. Their births were never registered with the UK, and the Netherlands does not as a rule allow dual nationality. At the time of their births there was no advantage to being British as well as Dutch. Brexit changed that perhaps, but not by a lot.
I think, provided you are not planning on settling in the UK, if your birth was never registered in the UK through an embassy you can get away with not admitting to being British by decent. They have no way of knowing.

Personally I am extremely glad I had my Dutch passport made in my married name, so it matches by British one. Normally they are issued in your maiden name, which would lead to problems.