Hi, yeah for reasons that I don't know, the BCN BA flight comes into T3, and the HKG flight goes from T5, so will just clear immigration meet up with my sister (got 4 hours) have a coffee and then go back through.
To add complication I'd like to add one bag in Barcelona and a second in London.
If any BA Checkin staff are reading, would be interested to know what the situation would be with this.
If I don't find out the answer, I'll definately post the result next weekend.