Originally Posted by
nonformality
There is no page that says that – what the GGL hotline told me is that when transiting, the gate agents need to check I have a valid travel document for my destination. Which I do. But alas.
i don't wish to be harsh, but you did originally say "
Gov.uk says no eta needed" and that you triple checked. are you now saying the only check you did beforehand was on a call to a BA phone agent?
tbh i am somewhat surprised they even gave an answer, they really shouldn't and like most airlines the position is usually "we don't give advice on immigration requirements". they simply do not have the tools available to give any such advice like this. again, i know this sounds harsh, but if you were a ggl you are presumably a reasonably frequent traveler and should really know you need to check these things yourself.
to repeat the earlier question - what evidence do you have, other than this call, that you did not need an ETA and could do that trip on an EU ID card without a passport? you will need something if you have any chance of an IDB claim.