I arrive long haul to T3 connecting to a T5 departure. I am BA Gold arriving F on BA and leaving in Y on BA. I’d like to check out the T3 Cathay and Qantas lounges in T3, using my OW Emerald card. Thanks to the posts above by and in response to PHLGovFlyer, I know how to get to the T3 lounges from T3 arrivals. Thanks all! My connecting flight from T5 is to EDI. Since this is a domestic UK flight I believe I need to clear immigration on arrival at Heathrow. Does that mean I can not or should not use the expedited route applicable for PHLGovFlyer, but instead need to exit T3 immigration and then get to the T3 lounges via T3 Departures? Also, can I expect to get thru from T3 Departures to T3 airside and the lounges with my T3 arrival or my T5 departure boarding passes?