Originally Posted by corporate-wage-slave

That is why it is possible that you have 2 claims here. But ultimately you have to make a claim against a first flight for that claim and a rebooked flight for that claim. The safest is BA188 on 7 June then UA161 on 7 June, and I don't have enough information here, in terms of timing, to say whether it is claimable. If you regard BA180 on 8 June as your start point then you are disregarding the event that led to you being on that flight, and if BA180 did have a legitimate reason for cancellation such as weather then you're a bit stuck. Moreover there is the broad point that after being cancelled off BA188 on 6 June (with proper notice), you ended up with a ticket dated 7 June, and in the final analysis you travelled on 7 June, so that aspect of EC261 was working. If UA161 meant leaving much earlier, and / or arrived into EDI more than 2 hours after the original BA timings then your case is relatively strong.