Originally Posted by
onobond
1. No, missing the first segment forfeits the rest of the reservation.
2. In formality, yes. In reality, BA seems not to bother, so for the occasional jumping of the last leg very small risk of any complications. Making it a habit may alter the odds, but many in the FT fora seems to get away with it, four or more times per year. It's good to know that the airline legally has the right to reprice the ticket according to segments flown.
3. The ticket price is not necessary proportional to the distance. Hang around here and in the TP-run thread, and you'll find many good deals travelling ex-EU. This phenomenon is not specific for BA.
2. I'm trying to understand what in practice this could look like if you've already paid for the fare - they send you a bill in the mail? I don't understand how they could possibly re-price at the end.