Managers who won't approve travel expenses till several weeks after the trip. Managers who will only approve FAA pay (upfront expenses for 30 days) till after the 30 days are up. Some project managers are extreme at micro-managing. Very poor at communicating what is happening. Plan on not knowing if you are going to travel till the day before. Plan on explaining every expense. For gas purchases while on the road, you don't need to submit a copy of the receipt. However, when entering that info into expense form...you must type a note explaining what, where, when, and why. Lets see...American Express says it is gas purchased at Exxon in Atlanta. So your note would read. While working on the such and such project in Atlanta, Georgia, my car was running low on gasoline and I had to purchase more. For purchase of food at lunch...there would be a receipt for 9.00 at Richie's Deli....so your explanation would read....on jan 3, 2009, I ate lunch at Richie's Deli in Atlanta, Georgia while working on such and such project for GDIT. I think you get the picture.