Be warned the following statemet applies to most employers: To put in a false expense claim will be deemed as gross misconduct will be met with summary dismissal.

However, rules get interpreted, bent or even followed to the letter if this is advantageous......

I always obtain currency exchange receipts for cash (uk), cash (at the hotel) and travellers cheques (at the hotel). I hand over the receipt with the worst exchange rate and I'm applying the letter of my employer's law in doing this (they insist on a receipt but do not specify which receipt). For longer stays, I keep a close eye on exchange rate fluctuations and get another receipt if this is necessary. I don't view this as cheating and I'm prepared to bet that those travellers who don't do this will often end up out of pocket.

In terms of things I would not want to answer questions about, if I have a drink I get the hotel to put it on a separate bill that my employer never sees. I apply a simple rule: If my employer doesn't want to pay for it then its none of their business!

Of course, there's the little things that hotels sometimes do for you without even asking. A couple of bottles of beer orderd to my room after a hard days travel get itemised as "room service breakfast" and time stampted at 06:00 the following day at one place I've stayed at.