Thanks everyone for the valuable information and feedback in this thread. I am writing because I did not see a mention of any special rules applying to a basic economy fare.

I am writing on behalf of friends who have flown the outbound (US-UK) legs of a BE itinerary to visit their family. While there in UK, their mother has passed away and they wish to rebook return to accommodate staying at least through the funeral.

They are inexperienced travelers and I am aiming to step in on their behalf, but at this stage they claim to have phoned UA and been told that it is not possible to change.

Any advice would be gratefully received so that I am assist them. Thank you in advance.

Lurker