Please excuse this question, as I am new to FT. Can someone please clarify just what the airlines consider to be improper use of mileage acct? I have several hundred thousand miles on several airlines. On a few occasions, I have let family or friends use my miles to travel. I always do the booking myself, and the taxes are always charged to my credit card. Since I'm not making money off this and not using a broker, is this considered ok by the airlines? No one using my miles has ever been asked questions regarding them.