Crediting to AA on mixed *A/OW PNR
 

I'm flying YUL-ORD-DOH-BKK. YUL-ORD is on AC (*A) while ORD-DOH-BKK is on QR (OW). I booked through Qatar Airways (issued by QR on QR stock) and my AAdvantage number is on file with them. Obviously I'm mostly concerned about crediting my QR flights to AA, but since I do have one segment on AC, I'd ideally like to credit that to another *A program.

Can I have different segments be credited to different programs? I'm worried that if I change the first segment to a *A carrier, something will go wrong and I won't be able to credit the QR segments to AA. How does all this work?

Get the AC PNR and change it there. I had a mixed ST/OW route and credited KL to DL and AA to AA with no issues. Just dont add the *A number on QR.

Whose ticket stock it is is immaterial; it’s the marketed flight that counts, and often the operating airline. There shouldn’t be any problem providing one FFN for AC, another for QR. Do keep the boarding passes in case QR messes it up and credits it to themselves.

What I would suggest doing is to not have any frequent flyer number in the booking until the 1st sector is completed and then go to the Qatar site and add it

Then , if eligible, you can claim the Star Alliance flight to one programme and let the rest then credit automatically to the AA account

This is a non issue, I flew this exact same routing back in February and needed to do the exact same thing with regards to flight credits, i.e. the AC segment credit to my SK account and the QR segments to my AA account. My AA number was in the booking originally.

At check-in at YUL I had the agent change YUL-ORD to my SK number (I honestly dont remember if all segments were changed or just YUL-ORD, but it doesn't matter).

At ORD, you have to check in again with QR anyways to get the QR issued boarding passes. At the QR check-in desk, I had the agent change everything back to my AA number. Just make double sure you're issued new QR boarding passes that have your AA number on them.

Everything posted correctly, it's really no big deal. No need to overthink it and leave your number off some segments and try for retro credit, or anything like that.

Why would you need to check in again? If on a through ticket , the check in agent should be able to issue boarding passes for the whole journey

AC does issue boarding passes for all flights however QR typically always wants boarding passes on their own paper stock, at least IME. Whether you check in again at the landside main check-in desk or at the gate, doesn't matter. Given the ORD situation with regards to transport between T2/T3 and T5, and coming from a T2 arrival on AC, it was much easier and quicker to take the landside bus to T5 and check in again with QR there (and make sure the freq. flyer number was sorted).