Originally Posted by
FatnLoud
Not my company exactly, but my major client is keen that I use their travel agent for airline bookings. I normally comply but on one job I was very busy and booked my own flights to the US. When I finally billed them my contact at the client sent me an email warning me that I'd made a mistake because the travel costs were "too low to be sensible".
What they probably really mean is that you were embarrassing either their own employees or their travel agent, with which they may have an undisclosed relationship.