Suppose that a person A booked a flight to the middle east from the UK. The Airline's Covid site advice was that PCR tests had to be done 72 hours prior to the flight. Suppose that A took this advice as accurate, had the tests, but at check-in A was refused boarding. The rule was 48 hours. The web site was wrong. A flew the following day at an extra flight cost of £1048. Then there was the extra costs of the PCR tests plus two extra taxi journeys. A complained but the airline have said it is up to passengers to ensure travel documents are correct. Suppose further that prior to online check in A received an email advising A to check on the airline's web site the Covid rules. Also, when one calls them the auto messages give the same advice. This would be fine if the airline's advice had been correct, but at the time it was not. Suppose that A has screen shot evidence of the incorrect page.
A now wishes to take them to the small claims court. I A has so-far failed to obtain a UK corporate address. Could A use their HQ address in a different country? Can A sue in the UK? If so, does A have to use a UK address for the airline? Is there any point in my pursuing this or do international companies that are based abroad have a blanket get of jail card?