Originally Posted by
TurtleCreeker
Jeffers8 is correct about the connection. I've connected many times at LHR coming from other European cities en route to my home base in DFW and have never been charged extra taxes when the upgrade cleared.
Agreed, and this is well-established in other threads on the topic. The current thread, though is about originating in the UK, with onward US connections, so this particular point (while true) is not germane to the discussion at hand.
Cheers.