This is kind of a grey area. If you are doing this on full-fare tickets, it would probably work. Bear in mind that the two one-way full-fare tickets (the parts you'd be left with in the end) are in all likelihood going to cost more than the single round-trip ticket.

If you are using discount tickets, cancelling the return leg of it will result in a recalculation of the fare, possibly requiring upgrading the fare to a one-way full-fare. Same thing for ticket number two.

In all likelihood the extra cost of the ticket vs that of the single round trip ticket is not going to be worth that extra 500 miles (nor the extra time you'll need to spend changing tix, cancelling segments, etc.)

One thing you might want to consider is that if you are flying from A to C, consider breaking the journey at intermediate point B. Book ticket #1 A-B, B-A and ticket #2 as B-C, C-B. This is called end-on-end ticketing and is perfectly within rules and regs. This would get you the second online booking bonus, however again pay attention to what this does with the airfares. If B is a hub airport, usually this will give you a higher total airfare than if you were to book the through fare A-B-C, C-B-A as one itinerary. The other thing is that if you are checking baggage, it's more of a hassle since you'll have to reclaim it at B and check-in there again.

Hope this is helpful. The real experts will now chime in.

FewMiles..

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