I flew in a few days back. The day before my flight I used the check in feature to pick my seat and made sure to be sitting with nobody next to me, right at the back of the plane. Fast forward to the flight and someone was given the seat next to me. Obviously I wasn't very happy about this but what could I do? Luckily after boarding had finished I noticed that the seat parrallel to mine, a set of two was completely empty. During check-in these cost about £30 extra if I recall correctly. Anyway, I asked the flight crew if it was okay if I sat there as I wanted to be separated from other passengers and he told me it was fine as boarding was over. So I did indeed sit on my own during the flight. However if you checked my ticket you would assume I was sat by someone. I'm curious as to what would happen if the guy I was supposed to sit next to tested positive, I'd assume they'd contact me and I'd be screwed even though I never actually sat next to him for the flight. But as one of the posters above said, I actually don't think they are really enforcing this rule for passengers who are travelling solo. The group situation I get that they might but as a solo passenger I don't think they will enforcing this. There are no written rules for it. Like, is it just the seat next to the positive person that counts? What about the seats in front or behind? Just one seat or will it be two seats distance from a positive test that will be quarantined. There no official guidence for this and so I really think they necessarily be enforcing it.