Originally Posted by
KARFA
As noted this is absolutely not correct. International passengers arriving at LHR and transiting on to DUB (or indeed any UK airport) go through immigration (it is the same queue for UK and DUB connections at the border) and security. You would have your photo taken as well as part of this process and this is reconciled with you at the gate when boarding.
Given that DUB is of course NOT a UK airport and to a casual reader that could carry that implication as other airports in Ireland are not mentioned, I think that could be better phrased as:
"International passengers arriving at LHR and
connecting on to DUB (or indeed
any airport in Ireland or the UK) go through immigration and reclearing security. It is the same setup in all UK airports, however in some cases - even when the airport has a connections provision generally - to connect onto CTA destinations the passenger would actually be routed landside and re-clear security with non-connecting passengers (i.e. it is the same queue for CTA flight connections as it is to leave the airport at the border) "
(Connecting as in airport design terms and immigration terms they do not remain in transit, or rather to clarify they are transiting the UK (having been given entry to do so), not transiting the airport.)