Hello All,

Just wondering if I travel on CX to LHR and then BA to EDI, do I need to clear customs and immigration in LHR? or I can connect straight to EDI?

Also If i am planning to use the AA Arrivals lounge, will I be able to get back into T3 to get the internal BA bus trasnfer to T1 for EDI?
Or do I need to get the tube to T1?
What are the transit arrangement in T3 to T1?

As I always transit in T4, I have not being to T3 for a really long time