My wife and I I have accumulated enough frequent flyer miles for us to redeem miles for a trip to China or somewhere in that region, assuming that we could snag the seats. The problem is the timing. We can not get away in time to avoid losing our miles due to United's policy of miles expiring after 18 months of no activity. I would like to clarify what that policy means. Do you merely have to book the flights using the miles, or must the travel be completed before 18 months has expired? What constitutes activity. Can we simply make charges to our United/Chase VISA card and that count as activity which would be the easiest? or Could we buy miles or give away miles to qualify or must we travel to constitute activity?