Northwest/KLM will cancel the next leg of your flight(in this case Amsterdam/Seattle)If you do not use the preceding ticket segment.Even if you notify KLM in advance that you will not be using that ticket (NICE /AMSTERDAM).In this case that ticket is in a sold out status but still no go!Hows that for business sense?

Airline fare structures are complicated and it is not always possible to take a global rule and have it make sense in a specific situation to which it happens to apply. I've flown through Detroit on my way to London or Paris on tickets that were less expensive than a seatmate who was terminating in Detroit. Airline tickets are priced far more on the basis of competitive forces on a given route than they are on costs. Fare rules are put in place to maintain the integrity of the fare structure, even though the results may sometimes seem counter-intuitive at times.

I think all carriers will cancel the rest of your whole itinerary if you don't show up for one leg. Even your return will be cancelled.

Linda, as far as I know you area correct. Some people think that buying a round trip tickets when they only want to travel one way is a good idea. But if they do this and buy a round trip tickets and do not use the first ticket their second ticket is cancelled as they were a "no show" on the first ticket.

I can't imagine why anyone would book a round trip ticket if they didn't plan to use the first segment. They should be buying a round trip the opposite way, so the first part is the part they NEED to use, and then not show up for the second part.

I agree with you Patrick, it has not made sense to me either, but I have known people that have done it. Honest!

Fares are based on the amount of route, or "market" competition as Flyboy has pointed out. I've never heard of any airline that doesn't cancel subsequent segments when the first one isn't used.

The probable reason the airline won;t "give in" on your particular situation is that the first segment is probably overbooked anyway..something else most of the airlines routinely seem to do.

In my case the segment i wanted to not to use is the first segment of the return trip-Nice /Amsterdam.We considered leaving early to spend two days in Amsterdam before taking the final leg home.The flight we wanted to give up is sold out-we asked for no compensation/nothing.KLM could sell the seats again and pocket $300 x2.Rules are rules we will use the orignal tickets.Thanks for your patience.

I did it once, did not use the first segment of the return flight. I had already a train ticket for that leg, and let the airline know (it was the same airline for all 4 legs) when making reservations. They asked to see a ticket copy at each boarding

It was in 1998 going to Canada.

Any airline will cancel the rest of your ticket if you don;t show up for the first leg of it. It is possible to save money sometimes by buying two roundtrips and only using half of each - but you must use the FIRST half of each and throw away the second - not vice versa.