There are small fees associated with redeeming miles on most US airlines. British Airways is also notorious for applying "fuel surcharge" fees (payable in cash

There are small fees associated with redeeming miles on most US airlines. British Airways is also notorious for applying "fuel surcharge" fees (payable in cash only) to mileage award tickets, running into the hundreds-of-dollars range when redeeming miles for business-class or first-class tickets.