I had some flights on Cathay Pacific recently that I would like to claim miles/points for retrospectively. As Marco Polo Club of Cathay charges a 100 USD membership fee, I will not use that program.
While I had planned to register and collect e.g. with BA Executive Club, I realise now that they require me to have been a member already at the time of travel, which I was not. Similar applies to Finnair Plus.
So are there any other Oneworld loyalty programs that would allow me to register and claim miles for a CX flight before my membership?