Originally Posted by
gya007
Thanks all! My parents are US green card holders, not citizens; I will be requesting wheelchairs. I just wasn't sure, if I should automatically assume that if it's the same terminal (T2), then there wouldn't be any immigration formalities. What you all have told me is re-assuring!
Even when changing terminals there is no need to go through immigration on an LHR transit, unless you need to collect checked bags (which you may need to on separate tickets), and/or your departing flight is to the UK/Ireland/Jersey/Isle of Man.