Originally Posted by
Ldnn1
Don't you enter the UK for a CTA connection to DUB? It's the same route as connections to domestic UK, as far as I'm aware, so even though you might have stayed within connections you will be technically entering the UK when you go through passport control at LHR, no?
yes, there is no way to avoid UK immigration when doing an INT-LHR-DUB transit even when staying airside. you enter the UK. this is the same for all similar types of connections where you land in the UK and are connecting on to Ireland - albeit in most other UK airports you must follow a route going through immigration and landside.