That is true. I lived in GSO (USA) but travelled frequently to BSL (CH). I had an office there and actually sourced my tickets there - trips always started from BSL. MY BAEC registered address was my office in BSL and it worked fine. I did not feel I was cheating as my company had puchasing agreements with BA, Swiss, LH. Using BA suited me, my company and BA. (I would not have been allowed to book trips 'off travel policy'). I usually managed over 2000 TPs per year.