I've never been denied when expensing change fees, even when it's just to catch an earlier flight because a meeting/visit ended early. I think I get alot of latitude because my I do alot more research on my own than our travel coordinator would, I find lower fares, and am willing to accept longer routings. I've even been able to expense gate upgrades (under $100) and lounge day-passes with no problems given they were greatly offset by the initial savings I had found myself. I think the fact that my company refuses to pay for business class, even on international travel and regardless of length, for anyone except the owner and president makes my boss (a VP) pretty lenient on other minor travel expenses.