I’ve heard of people giving mileage or tickets from mileage to other people and to charities. Is it legal to sell your “miles”? 
Legal, apparently so. Allowed, no it is not. According to smartertravel.com there are no laws saying no, but most contracts for the airlines state you are not allowed to sell, trade, or barter your miles.
However, I am sure there is a way to do it. This site buys and sells miles.
Nothing illegal about it but it all depends on the policy of the airline.
United mileage is non-trasnferable, and sale is explicitly and bold-facedly prohibited.
US Airways allows donations, and redemption for anyone you name.
Aeroplan also allows you to donate miles to charity or to transfer them to other Aeroplan members.
United prohibits transfers at death or divorce and alike. The op is asking about gifts. I can assure that you can use United miles to give someone a free trip. I have done it several times. I took my entire family to Hawaii on United FF miles.
I can gift my miles to anyone. I cannot transfer them.
United certainly does allow you to redeem an award for a ticket to give someone else:
The OP is a little general, “giving mileage or tickets. . .Is it legal to sell your ‘miles’?” though. You can’t sell your miles, or sell a ticket:
But the answer to the OP is that it is not governed by law, but by airline policy.
One thing that’s interesting is the IRS says the airline miles ARE NOT income. Because they are property of the airline. However if you sell them then they ARE income and that must be reported as such.
This was a big issue when our company gave out airline miles as bonuses. Our controller didn’t take note and the IRS came back on two people. It was a lot of miles though over 200,000 miles transfered as a bonus to the employees
One thing that’s interesting is the IRS says the airline miles ARE NOT income. Because they are property of the airline. However if you sell them then they ARE income and that must be reported as such.
This was a big issue when our company gave out airline miles as bonuses. Our controller didn’t take note and the IRS came back on two people. It was a lot of miles though over 200,000 miles transfered as a bonus to the employees
The easy way to sell them is to find someone you know that needs a ticket, redeem your miles and get a ticket in their name and have them pay you something less than the cost of the ticket. I am sure that happens all the time although it may need to be family member under certain airline policies.
One thing that’s interesting is the IRS says the airline miles ARE NOT income. Because they are property of the airline. However if you sell them then they ARE income and that must be reported as such.
This was a big issue when our company gave out airline miles as bonuses. Our controller didn’t take note and the IRS came back on two people. It was a lot of miles though over 200,000 miles transfered as a bonus to the employees
Although no one has had the sense to mention it yet, airline miles are NOT income according to the IRS. Be careful though because you can get in big trouble if they are sold and you don’t report it.
American allows you to “gift” your miles to another person, but there is an insanely low limit to the number of miles- like less than 20,000 IIRC.
Just to add one more thing, if you do get caught selling your miles, the airline can, and usually will, close your account. Goodbye miles.
This may not sound too bad if you have 30-40,000 miles, but if you have a million miles in your account, it is gonna hurt big time.