Brushing up on xONEx rules
 

Sorry it's been a couple of years or so since I last booked one of these, so need to refresh my memory on the rules...

If I buy a xONE4 originating in 'Europe' ;) , fly over to Asia, on to North America and transit directly to South America where I use up my 4 segments allowance, could I then buy an additional segment to go to Mexico (classed as N America) before heading back to Europe or is this counted as entering N America twice? (ie only solution is to buy an additional continent and to fly to S America from Australasia?)

You are allowed to enter N America twice provided that one of the entries is a transit either to or from South America, so that isn't a problem.

Moreover, intercontinental segments (which is what both the SA-MEX and the MEX-Europe segments would be) don't count against any total except the 20 segment maximum. That is fixed - you can't do 21 segments by buying additional segments. Moreover additional segments can only be within continents, not between them, so there is no way you could buy SA-MEX as an additional segment on the xONE4 ticket.

Having said that I don't see why you couldn't do the SA-NA (wherever to MEX) segment as a separate ticket if you have already hit the 20 segment limit, but in that case you need to be looking for which of the 21 segments you want to do would be the cheapest to replace with a standalone ticket.

In summary, if you aren't hitting the 20 segment limit then you can do what you propose without the need to buy additional segments. If you are at that limit then you need to replace one of the other segments with a standalone ticket.

Thanks christep (hope you're well, btw). Think I've got that part of the problem solved. As for Europe as the continent of origin: if my starting point is IST, WAW or CAI and I want to use up my other European segments (let's say LHR-MAD-LHR for purposes of illustration) am I limited to just a single > 24 hr stopover in London or can I do it both ends? Eg IST-LHR stopover for a few months, resume itin, return to LHR, stopover again for a few months, then LHR-MAD-LHR-xfer IST.

Hope that makes sense?

If I understand the question correctly then two stopovers in London, one at each end of the itinerary is no problem - I sometimes do Ex-CAI AONE3s that way (with a LHR-IST-LHR-CAI mileage run at the end). But obviously you can't also stopover in MAD since that would be 3 stopovers in the continent of origin.