Originally Posted by vedette
If I go straight to London, can I then take a two- or three-segment trip out prior to departing for Delhi? That seems to be the implication from PhilH's post below.
Or could I take a side trip first, such as to Malaga, then Barcelona and then to London?
Yes and no. You have the relevant *files and some good answers quoted above, but let me explain it to you this way.
First, you're limited to 4 segments total in Europe (the fare is really designed for you to bounce back and forth twice from your origination, not do what we almost all do and originate someplace cheaper) so in practicality you have 3 segments to play with while in Europe since you seem to be planning on going to LHR to go to DEL. However, also add in there that unless you're planning on flying into MAD from another continent (NA/SA more than likely) to end your trip (IB/AA have directs IIRC) you'll need to save one of those segments to get back to it once you've flown into LHR/FRA/wherever.
So, yes, you might have 3 segments if you plan out very carefully, but more likely two. So yes, more than likely you could do MAD-BCN-MAD if you want...but...
...add in the restriction that on your entire Europe trip you can only have 2 stays at locations in Europe for more than 24 hours (the stopover rule). So yes, you could do Barcelona, but you'd also have to be very careful to make sure your return to in MAD and subsequent travel to LHR on the way to DEL is less than 24 hours each (LHR less than 24 hours will also save you a decent amount on taxes, incidentally, and is not at all hard to do), assuming that if you were to fly into someplace other than MAD on the return you stayed there. (Then again, if you did MAD-BCN-XXX-LHR and made sure to fly back into MAD when you're finishing you're trip you could stay in BCN and XXX for however long you wanted as long as you made sure LHR was less than 24 hours.)
So yes, you can, but you have to plan it accordingly.
Also, if my departure city is going to be Madrid, do I have to buy my ticket through a Spanish agency? I live in the US.
The way the rules work is that you have to buy your ticket from either an agency in Spain or a oneworld airline office in Spain if you want the (cheaper) Spanish price - otherwise if you pay for it in the US, you pay the higher US rate even if it originates in Spain. Most international offices are more than happy to take your credit card number over the phone or by fax and have the ticket waiting for you to be picked up (some will even offer to ship it to you in the US, which I've never understood how they get away with). However, you can (and should) book it through your local oneworld RTW desk (usually of the airline that is doing the big overwater segments); trying to get an international agent that may not be perfectly fluent in English (assuming its your native tongue since you live in the US) to deal with all the stupid OWE rules when you're not positive of them yourself can be a little hard.
Hope that clears things up and it gets easier as you get more experience!