UPDATE: The guidance has been updated where they have now put this in the guidance

In line with temporary guidance, carriers (such as airlines and ferry companies) may allow you to travel if you have both:

• an expired UK passport, issued in 1989 or later
• a valid passport for one of the nationalities that can get an ETA

However dual citizens cannot apply for the ETA.

https://www.gov.uk/guidance/electron...al-citizensAnd the saga continues. A couple of weeks ago the guidance did not have the expired UK passport issued in 1989 or later.

Now dependent on which airline you use certain carriers like British Airways employ overseas staff who are used as check in agents. They check your tickets and travel documents if flying from outside of the UK. As long as everything is in order they will let you on the flight.

But basically....just get a British passport. Or give up British citizenship entirely. It's a lot less hassle than trying to second guess what might or might not be accepted in this initial period.

As others have said, the UK insisting on a UK passport for entry is only catching up with what others (like the US) have always done. IMO, it's really not hardship carrying two passports. Small price to pay for having dual citizenship.

Yout could also fly into France and take a small boat across the channel, that sounds like you believe that may be an easy risk free option. Bit like driving across the US/ Mexican border

There are passport wallets that hold up to 8 passports. I wish I could just use my passport card instead of a full passport. Thinking about this, I don't need my US passport to be stamped , or visa. I only need it to get back into the US. Is this an option?

Err there would be a hassle and hardship if you lost both passports the day before you flew back.

As usual this policy has been badly thought out and has already been changed to now being potentially to carry an expired UK passport issued after 1989.

Yes I am being a PITA as there is no specific LEGAL requirement to enter on a UK passport. Legislation (the Law) will always override a policy. Until they amend the law then this can be legally challenged. Sort of like being arrested for an offence which is not an offence by law.

If you read the links it quite clearly states

There isn’t a specific legal requirement for British citizens to travel on a British passport but in practice pre-departure checks for UK-bound travellers make it difficult to travel to the UK without one.

A British dual national travelling on a foreign passport is not supposed to use any of those. They would be ineligible for an ETA, eVisa or immigration permission due to their British citizenship.
From 25 February 2026, the Home Office will be fully applying the ETA requirement. The Home Office is advising British dual citizens to make sure they have a valid UK or Irish passport or certificate of entitlement if they will be travelling on or after that date. If they don’t, they may not be able to board their transport to the UK.

See depending which link you use how you are given conflicting information. NO LEGAL REQUIREMENT to travel on a British passport. NOT SUPPOSED TO, MAY NOT BE.

Clear as mud.

Well, I posit it would equally be a hassle for anyone with just one passport to lose it the day before they travelled anywhere

MIght not be a bad option. I hear if you do it that way, you apparently get a free 5 star hotel in Canary Wharf with sumptious breakfast buffet, a new Iphone and daily spending allowance. Should easily offset the cost and hassle of simply just getting a UK passport

This is a mess of the government's creation by outsourcing border control to the airlines. They have created a Catch-22 situation whereby they legally cannot require a British citizen to present a British passport to board a flight to the UK nor obtain for an ETA on their second eligible passport but equally a British citizen without a British passport or a valid ETA will be refused boarding by the airline who wants to avoid a Section 40 fine.

The reality is that, if a dual British citizen wants to apply for an ETA on their second passport and continue to travel to the UK as a visitor on it as they have done in the past, then there's no legal or practical impediment to them doing so.

Thank you My Lord I rest my case as well.

So, I happen to be flying to Heathrow on day 1 of the ETA enforcement. At check in in the US, for the past 20 years I have had them scan my US passport (but have British one available if asked). This time however, they wanted to scan my British one. Which we did, no problem....until I got to security and noticed TSA Precheck was missing off my boarding pass. So had to stand in the slow line. I'm guessing the scan of the UK passport has thrown it out, as the global entry/Precheck is tied to the US passport. Something to think about for anyone else travelling soon, if you have Precheck, make sure it's on the boarding pass before you leave the counter...

Precheck isn't tied to any ID or document, just the booking and then the boarding pass. Sometimes I find it disappears off the Boarding Pass but that is not to do with the ETA thing or the Passport shown at checkin. Usually the airline staff can fix it if you notice before TSA

Yep....I looked up my booking after the fact, I think by them changing the passport at the desk, it also cleared out the other boxes I had filled in at time of booking (my trusted traveler ID and contact boxes were blank). First time in 7 years of having Global Entry/Precheck I've had an issue, will remember to properly check the boarding pass before leaving the desk next time.

A nuanced point on UK/US dual citizenship: I'm a UK-born UK citizen who naturalized as a US citizen in 2008. At the naturalization ceremony, I swore off any allegiance to all other foreign countries.
That pledge means a lot to US authorities, but nothing to UK authorities. I immediately got a US passport (yes, the next day after naturalization) and traveled to the UK on it the very next day. I've never used my UK passport (nor applied for a renewal) since naturalizing.
The point: I can honestly attest that I'm ONLY a citizen of the USA. This allowed me to qualify for the security clearances (that are not open to dual citizens) that were essential for my work. Having said that, the UK authorities still consider me a UK citizen, so in a sense I have two citizenships. I did need, and get, an ETA to travel to the UK last year on my US passport.
Now that I've retired (dropped my security clearance), I suppose I could renew my UK passport and avoid ETA fees.

You're not only a Citizen of the USA though, the US can't revoke your foreign citizenships for you. Only if you formally renounce your UK Citizenship with the Home Office are you no longer a UK Citizen, only they matter.

I'm very surprised you hid your foreign Citizenship for security clearances, that seems like a very serious omission that's easy exposed (USCIS knows it) and liable to serious prosecution I'd imagine!

I highly doubt there will be any criminal type prosecutions as Immigration Law is mainly Administrative not Criminal. There are certain provisions within Administrative Law where criminal sanctions could be sought however most will adopt a system of Administrative sanctions i.e fines or other.

Over the past several years, states and localities around the country have increasingly

considered and used state and local laws to impose criminal penalties on undocumented

immigrants. At the same time, the federal government has increasingly chosen to criminally

prosecute individuals who enter or reenter the United States illegally rather than rely on the

extensive civil enforcement scheme under the federal immigration laws.

https://www.aclu.org/sites/default/f...IC_VERSION.pdf