How do I get status and credit card benefits if I book a flight itinerary where some of the flights are operated by a different carriers ?

For example, if I book a flight itinerary on United, and it includes a segment operated by Air Canada under a United codeshare, will I be able to get my Air Canada status benefits, such as priority boarding ? I don�t have status with United, but I would still need to use my United MileagePlus account number when making the reservation, to get some benefits from my United credit card.

Another scenario is making a reservation on AC, which includes a segment operated by United. How will I receive my United benefits, such as priority boarding and economy plus seat, if I make the reservation with my AP account ?

I don�t understand how this works when there are multiple carriers involved in the itinerary, so I would appreciate it if anyone can explain how this works.

Do you have status with air Canada (like 50K or something?) or are you asking about credit card benefits?

Yes, I have 25K status with Air Canada, as well as a premium AC credit card (TD VIP). With United I don�t have status, but I have some benefits such as priority boarding from the United Quest credit card. Also considering purchasing United economy plus subscription, which provides the option to get economy plus seats (extra legroom) on all flights, instead of having to purchase this upgrade separately for each flight.

If I make a reservation on AC, can I somehow also include my United MP account number, so I can get the United benefits on the United-operated segments of my reservation ?

Quick answer is that you can only have one account number per itinerary, but you can ask them at the airport to manually change one or more segments from AE to MP or vice-versa. The challenge is they often don't do it right and everything gets changed even if you only wanted the number changed for one segment. It's then very difficult to go back and get segments re-credited to the correct program.

A better strategy is likely to credit to the program on which you want to accumulate the miles then show your credit or other benefit card to get the benefit you want.

With UA, you can just call them after booking, and get them to change your number, and it won't flow back to the other systems.

Great, Thanks !!! Also I guess for the economy plus seat selection, I can just do it on the United website, after making the reservation on AC�s website.

That way I get all the AC status & CC benefits (including luggage, priority, lounge), but I still get the United economy plus seating and priority boarding on the United segments.

This question is more about being able to use the frequent flyer benefits of each airline, in a mixed airline itinerary, and not so much about crediting the points or miles to one of the programs.

Yes you can typically use the credit card benefits whether or not you credit the points to the program. As I posted above, just pull out your credit card if you need to (you may want to show it to the gate agent before boarding to make things smoother).

I believe in the case of reserving Economy Plus, those segments must be credited to Mileage Plus, so follow canadiancow 's advice on that.

From the TD terms:
So no, technically, showing the card is not sufficient.

UA benefits should be discussed in the UA forum, but in general, even if something is possible without putting that program's number on the segment, that doesn't mean it will be easy.

But I recently-ish flew AC SFO-YYC-FRA LH FRA-CPH, and I had my AC number on the AC segments and UA number on the LH segment. Those are all 1A, so it required getting someone competent to do it (though everyone I spoke with was competent about this). But it all worked fine. I received the benefits to which I was entitled, and the miles credited where I wanted.

I guess you made this reservation with AC, but what would have happened if you booked the same itinerary with United ?
Would you be able to get your AC benefits, such as priority boarding or other things you�re entitled to based on your AC status ?
If reservation was made on UA, then AC wouldn�t even know your AP number unless you do something to let them know , right ?

SHARES and 1A tend to not be great at replacing FQTVs in the other system after booking. So it would be the same thing. I generally book (through AC or UA) with my AC number, then call UA to swap to my UA number, and that gets me UA on UA and AC everywhere else.

But it also depends on my goals, which are different now than in December.

But I've done stuff like this for years, and I've never accidentally credited a flight to the wrong program, or missed out on any benefits.