Has anyone had any actual experience of not completing an xONEx? How readily do the airlines co-operate to track you down? And how much sympathy might you gain if they chase you?

It seems I'm about to find out, largely on the informal (foolishly followed?) advice of an AA agent at heathrow. I'll share what happens. My somewhat unusual story so far:

I've reticketed thrice already. All paper tickets. Original was on CX stock in London, first reticket with AA in Toronto and sane, second re-ticket in Argentina with AA again and messy, third re-ticket was a joke by FINNAIR - after half an hour struggling with the system the agent just hand wrote tickets with open dates.

I'm in London with mad-ist,cdg-lon left to fly by Sept 1st. I was going to do that last week but things went bang (or rather, thankfully they didn't). After trying to handle this on the phone with FINNAIR and the AA rtw helpdesk I eventually just went to heathrow with the aim of re-ticketing again with just cdg-lon or something (I'd take a cheap eurostar and fly back same day).

When the supervisor worked out that all I wanted to do was comply with my xONEx and had no actual interest in traveling, she advised me to do nothng - that in practice nobody would ever notice (in my messy case at least) if I just threw the coupons away. AA is the only OW FFP I care about, which made a difference to my decision to take her advice.

Paper tickets seem to be a deal of extra hassle all round and opens scope for all sorts of unreliable rule breaking. I suspect my issue won't even be spotted for that reason. Fingers crossed.

A somewhat less risky option would be to throw away the mad-ist coupon and fly your existing (and last) cdg-lon segment, all without a reissue.

Airlines go after chronic offenders -- people who have dozens or even hundreds of round-trip flights and always throw away the return coupon, for example. I have never heard of any airline going after a first offender. If you fly often enough, eventually you wind up breaking some fare rule, no matter how much you might try not to ... the rules are so convoluted that even agents don't know most of them. Obviously the RTW ticket does require flying RTW, and not ending in your home country breaks this rule (hence Viajero's excellent suggestion, technically that puts you 100% into compliance with the xONEx rules). Even without flying the last sector, in practice CX won't come after you (it is only the issuing airline that counts, CX in your example -- AA is not involved in any way with your ticket). You have to make your own decision about this, but I'd say it is low risk no matter what you do.

You'll be fine. Don't worry. Throwing away coupons is one of the advantages of paper tickets. Doubly so if everything is open-dated.

I too am interested if there are any first hand experiences about this being a problem. It is often rumored but I have yet to hear of an actual case.

It's the first coupon which if not flown causes a problem. From then on, YMMV depending of course of what you are trying to do.

The Brazilian government does this systematically, at least for all students and staff of Brazilian universities who will be staying abroad more than three months. They actually issue two round-trip tickets, one with the correct departure date and the other with the correct return date. This has been doing this for at least 10-15 years.

I buy around 3 RTWs per year, typically buying it at the 'cheapest' place. It was BUD 4/5 years back, then ARN, then CAI, now IST. Very often i was not using the last sector to get back to the starting city. Never ever anything happened.

Do you no-show the flights, or cancel res' ahead of time?

One of the advantages of open tickets is there is no reservation to cancel. I have done this a couple of times with the last sector, one with a round trip mileage run to IST, and once even a transoceanic coupon... Never a problem, but always with paper tickets and open coupons. I really can't see how you'd be able to miss segments in the middle of the ticket with an e-ticket.

I have just the CPT-JNB-HRE legs left of an e-ticketed AONEWC4 (with actual dates at the insistence of BA when issuing). The only reason I would want to go back to HRE is to start another *ONE* trip - but the latest fare increases have put paid to that idea. I am trying to re-issue with CPT-JNB-MRU once BA starts the MRU flights, but BA in HRE says I can't. If they don't relent I plan on not using the last coupon. From what I read here this going to be some sort of problem?

I can't see why BA should mind since they have to provide one less flight. Besides when I missed my flight to HRE BA just pocketed the money and I had to buy another ticket.

Any reason why not? The starfile (AA) rules for an ex-Africa AONEWC4 allow termination anywhere in Africa. Have the rules changed recently or is BA going on its own, different set of rules?

Savings provided by any ex-IST, CMB, etc xONEx necessitate, by definition, actually having to start from the city in the first place. As noted, not travelling the first segment is the absolute no-no. Notwithstanding the technicalities of the xONEx rules, why would an airline be bothered to chase you if you fail to finish at your departure point/zone?

I had a similar issue recently (same problem, different location) with a BA issued ticket. It was resolved by calling a different BA agent, and having the rules to hand and being able to quote the relevant bit.

After 1-year from the date of the first flight, one could always say that the remaining flights on the ticket have expired. I don't think they can force you to fly.