Originally Posted by
mshaikun
Back to back ticketing is against the rules but you are unlikely to get caught. Checking in and not boarding will not get you miles. The plane will not wait for you.
If you are concerned about getting caught, just book the two round trips with different carriers.
If you can plan your business trips well in advance, rather than "throwing away" the second legs of your round trips, book them for a tme when you think you might go back to that destination.