In February 2016, BA announced the end of its Unaccompanied Minor (UM) program for children 12 and under, citing costs. So for UMs under the age of 12 booked on multi-city itineraries on Oneworld alliance tickets, this can a problem. For example, a UM under the age of 12 traveling from Miami to Boston to London Heathrow can fly alone on the American Airlines segment from Miami to Boston, but cannot fly as a UM on BA’s Boston-London segment.