Originally Posted by
andox
Yes, it is, assuming the routing is eligible for SDFC (i.e. you're not connecting from somewhere to LHR on the same fare basis). I have done this several times.
Thanks! ^ EXP desk said that I would have to pay the fee and I didn't have time to HUCA. LHR ticketing desk was also completely unaware that you could SDFC the route, but they eventually sorted it out...