Maybe this has changed lately as they have updated this site.
I was fairly sure I had read earlier somewhere a rule that I mentioned above, but nevertheless, even better now!

I logged multiple AY2XXX flights last year operated by Flybe to my AA account. Always 500 mile minimum + 500 extramiles for plat/explat benefit. This year haven't done so as been putting my miles to AY - decided to go for AY Plat. Except today used my AA FF# on these flights - I expect the miles be posted sometime next week..

Just to update it got all sorted after I called JAL and selected the frequent flyer option - they couldn't do it but put me through to Finnair who were very helpful and got me my seat! So all ended well....

I'm in the same shoes - after years of neglecting AY+ I decided to go for AY Plat in 2015. I calculated that 3 months into the membership year I'd be around the 110k mark* and took the chance that I'll make 40k more during the rest of the year. As most of these flights are on AY C longhauls + their EU feeders, the earnings are really good.

*and the unfortunate fact that my BAEC year is in the middle of said 3 months' period would've meant only 600-650 TPs to renewal.

I just ran into an unbelievable codeshare problem that made me think of the computer says no jokes.

I have booked HEL-LHR-SFO // DFW-JFK-HEL. HEL-LHR is AY, LHR-SFO is AA flight number, BA metal because AA doesn't fly international ex-SFO and because I need the AA segment to meet the status requirement for AAdvantage.

(DFW-JFK is AA and JFK-HEL is AA flight number, AY metal because the AY flight number would have cost me approx. €200. I don't understand how that is possible with the joint venture, where usually the price stays the same no matter whose flight number you use).

The booking has four booking references, one for AA and one for AY/Amadeus outbound and one for AY/Amadeus inbound. There is a 4th one, as well, issued by BA.

On the LHR-SFO flight I can either choose a seat by paying for it in advance, or choose it for free at check-in.

At T-36 I go to ay.com to check in. I use the AY reference. It automatically issues me a (bad) seat on the BA flight and a BP for both HEL-LHR and LHR-SFO. Calling AY doesn't help, they say they can't change the seat on the BA flight.

At T-24 for the LHR-SFO flight, I go to ba.com to change my seat. The BA booking reference works, but only allows me to reprint a boarding pass, not to change the seat since I've completed check-in. When I go to ba.com and insert the AY booking reference, it wants to redirect me to AY.com for check in. With the AA booking reference it finds no booking at all.

Calling BA, they tell me that with the BA booking reference, they can't see a ticket number and as far as they are concerned, I don't have a ticket and therefore can't check in (even if I already did). Then I give them the AY booking reference. They can see that I am checked in and want to redirect me to AY.com to change the seat. After I explain them that it doesn't work, they argue, then try for themselves and finally agree, then talk to a supervisor for a lengthy time, only to let me know that there is no way they can change the seat other than at the airport. Well, I know that at HEL they would give me the same story about not being able to change seats for a BA flight and at LHR, I would approach the desk maybe 1,5 hours before departure, so there aren't going to be any seats left.

They also tell me it's an AA flight. I tell them yes, the flight number is AA but the plane is BA. This doesn't help.

So they offered to cancel check-in completely.

I thought this is the worst suggestion to do and I would be completely crazy to agree and then thought, okay, let's go for it just to make this fun. It's still 18 hours to take-off so there's plenty of time to re-check-in if need be. So I let them cancel the check-in.

After this, I went to ba.com and typed in the BA booking reference. Now it worked and let me check in for the BA flight and choose a seat and print a BP. After this, I went to ay.com because I assumed I would need to re-check-in for the HEL-LHR as well. But on that site, it said I was already checked-in and everything seemed okay and I reprinted a BP for the AY flight + checked that also ay.com showed me the new seat for the BA flight to SFO. It did.

So in the end, it somehow worked. But for next time, I am going to follow these rules, whether there's a codeshare involved or not. Doesn't make the OW transfer a very smooth experience, though.

If you are on two separate carriers, (might only work on AY+BA combo):
- do not check in when the first flight is available for OLCI
- when the second flight is available for OLCI, go to the website of the operating carrier of this second flight AND make sure you have this airline's booking reference handy for OLCI
- do not accept if second airline tries to redirect you to first airline
- OLCI for second flight
- go to the website of the operating carrier of the first flight and OLCI

ffay005: I have the same problem now, flying tomorrow HEL-LHR-KUL with AY/BA. Did OLCI on AY and was not able to change seat for LHR-KUL. Now cancelled the OLCI on AY site (and somehow lost my preassigned seat at the same time).

LHR-KUL OLCI opens in 4 hours. How were you able to deny BA redirecting you to AY OLCI?

HJP, I believe LHR-KUL doesn't codeshare with AY, so your flight number is likely BAxxx. Therefore, this shouldn't be a problem on the BA site.

I have had similar issues with my booking as well. To sort this out before check in, I usually have to call BA and ask yet another (fifth) PNR/reference for Amadeus. This is some sort of "real" reference number for BA, and the one in your e-ticket recipt is just "ghost" reference to link the bookings to Sarbe. With the "real" reference, I have been able to change a seat and check in for BA operated AA/AY/IB/CX coded flights.

Yes, both HEL-LHR (flight BA6033, AY-operated) and LHR-KUL (BA33) are with BA flight number, but because the first flight is operated by AY the BA MMB says now " Your flight is operated by Finnair. To proceed with online check-in, we will transfer you to the Finnair website."

MMB also indicates that check-in for BA33 is open already, maybe because of the HEL-LHR connecting flight before that. T24 for BA33 is in 100 minutes...

EDIT: No luck after T24 either, all paths lead to AY OLCI and there is no chance for changing seats on BA flights. Generally BA seat selection for OWS is a joke compared to AA/AY, I try to avoid them in the future for sure.

HJP, you will need another pnr. Try logging in at BA MMB and see if you can find it there. If not, call BA. The pnr should be different from the one that you have used previously.

Might be that it won't work in your case, though, since both your flights are BA-coded. In my case the first flight had AY code.

After all the hassle, I'll avoid BA as well unless it's BA all the way and I can check in with them the way it's meant to be.

I started the olci on BA with BA pnr, that redirected me to AY with a separate AY pnr. So no luck in this case...

You should able to (re)check-in on BA.com once check-in for the first flight is closed - so just before boarding at HEL. But by that time, there probably won't be too many good seats left.

I have hard time to understand earnings for my upcoming flights, thinking whether to credit AA or to AY.

Flight operated by BA, AY code, booking class O how much I will earn?
Flight operated by BA, IB code, booking class S how much I will earn?

Will also try the trick that ffay005 suggested to first check-in at BA site and only after that in AY site.

For crediting to AY, see https://www.finnair.com/fi/gb/finnai...-points/flying

For AY code, see Finnair code-share flights without a ticket type.
For IB code, see Iberia.

In particular, AY O earns 50%, IB S earns 25%.

Just explained another way:

When flying oneWorld airlines, the rule is simple - in your desired progam look at the earnings table for the marketed airline (the flight number).
It doesn't matter who is the operating carrier (as long as it is another OW airline, or OW affiliate)

Codeshares are much more tricky in Star Alliance.