Refundable fare confusion
 

I'm noticing that AA offers refundable fares for flights that I want to book on BA which does not offer a (reasonably priced) refundable option.

I am choosing Premium Economy JFK to LHR and Economy return to JFK. Onward is the PE refundable fare and return is Main refundable fare, which add about $300 extra in total.

Now I'm reading the fare rules - JFK to LHR fare code is OHN4C1P9 and LHR to JFK is OLN0C2M9. Both fare rules say "BEFORE DEPARTURE REFUND IS PERMITTED. IF PASSENGER FAILS TO CANCEL BEFORE ORIGINALLY SCHEDULED FLIGHT THE TICKET IS NON-REFUNDABLE. AFTER DEPARTURE THE TICKET IS NON-REFUNDABLE."

However once ticketed, the endorsement says the following:

Endorsements/Restrictions

NONREF AFTER DEPARTURE/RESTRICTIONS APPLY

Anyone familiar with the refundable fare - what if someone flies the first segment and then cancels the rest, does the ticket become non-refundable after flying the first segment? Or will the price be recalculated and the rest refunded after taking the first segment out?

On AA, if you cancel the return after flying the outbound, this usually triggers a credit or refund for the unflown portion (which is often not exactly 50%, but specific to the actual fares used for the outbound and return which could be different) - it does not reprice the outbound you previously flew.

As to whether that ends up being a refund or credit, the usual interpretation is that the return remains refundable to original FOP unless you fail to cancel the return before departure of the return. Simply flying the outbound doesn’t make the return non-refundable. The goal of these kinds of conditions is to prevent no-shows. That said, I don’t have any direct experience trying to refund a fully refundable paid ticket after flying the outbound, so perhaps others can add their experiences.

It sounds pretty clear to me that the ticket becomes nonrefundable once you depart on the outbound segment.
So if you cancel the return, you’ll have a flight credit, but you’ll only be able to use it from Europe back to the US, and the value won’t be able to be determined until they reprice the journey (using historical fares most likely) of your flown outbound + new inbound.

I have no personal experience with cancelling a return flight under these circumstances, but it may be worth noting that OW transatlantic flights (which the RT ticket you describe would become if the return flight is cancelled) are often more expensive than RT's.

To avoid complications and assuming it doesn't cost extra, I always book refundable tickets separate as two one-ways under different record locators.