I work for a fairly small company, and we don't have a huge policy manual that covers every possibility, so it comes down to what my boss will approve. Luckily, he is pretty reasonable. I have never had to pay a luggage fee, but as long as it's not for bringing home 50 pounds of duty free booze or something, I don't see where I would have a problem. I have expensed the buy-up to United E+ in cases where I needed to work on the flight. A previous poster mentioned a prohibition on buy on board food. I've never expensed any, but if I got in a situation where that was my best option for eating while on a trip ( I hope that never happens), I don't see why it should be a problem. It certainly is no more expensive than eating at an airport.