Sharing some reticketing experience with BA for an ex-CAI DONEx -- I recall there being a thread more specific to that but can't easily find it.

As mentioned by many others, reticketing with the AA RTW helpdesk was rejected as they didn't have a filed fare exCAI and refused to reticket. I tried briefly with CX and JL but in the end was able to do it with BA sufficiently easily I didn't explore if those would have been possible and cheaper on surcharges etc.

The most useful thing I learned which I've not seen mentioned here is that BA has a RTW helpdesk in Europe whom you can email: [email protected]

Emails seems to go into a queue which then takes ~2 days to get picked up, but once picked up you get a specific agent to work with whom you can ask to speak to (they'll call) and will generally be more responsive on emails (sometimes same day, at least next day). I guess there's a risk they'll be out that day but it all worked really well the two times I used them. I'd avoid ticketing with BA due to their higher fuel surcharges policy but if there was reason to use BA I'm now almost as happy doing so as with AA and their RTW helpdesk (which I prefer as you can directly call them 7 days a week).

The desk is only open during EU working hours Mon-Fri IIRC so I did also do some date changes via calling BA. That was generally very painful until I found an out of hours number which worked far better: +44 191 246 3933.

As with all my prior AA reticketing experiences, it was impossible to get a breakdown on how the taxes and surcharges were being calculated. I tend to use ITA Matrix to look up one-way pricing to see likely taxes and surcharges and it was broadly correct. I did learn that BA at least will load up fuel surcharges for flights after a stop in Brazil or Hong Kong. I had previously hoped that the laws there preventing excessive fuel surcharges for tickets from there would apply but BA not unreasonably said they didn't given the ticket was not originating there. I'm not sure if AA et al have the same policy.