Originally Posted by
TheFlyingFoodie
If you end up having to go landside take a taxi between terminals. I've done this before and it is much faster than the bus BUT tip the driver 20 GBP (or more if they're particularily friendly) since they were likely hoping for a fare into the city.
A convenient though expensive option, even without the tip.
But cab drivers on short trips from LHR are allowed back to the front of the cab line, so although they moan, they don't deserve an extra tip!