I consult for many firms that request I use their corporate code, but I tend to look at both the code for my firm and for the client, to see which is better. It is to the benefit of the client that I work between the two and, oddly enough, even use my AAA code.

I think the issue here is the misuse of codes. We all know that there's a sticky with several pages worth of corporate and promotion codes. The question is, is it right to use if you're not engaged in a legit activity related to the code?

I think it's a lot like speeding. Feel free to use the codes, but, for the love of god, don't whine if Marriott calls you on it. There's nothing like listening to someone who gets snagged cry about inequity of being caught.