How to add alternate Frequent Flyer number to a reward booking?

Hi All,

When you book a reward flight usually it auto populates your FF number with the program you booked it on (e.g. my SQ redemption has my KF number on it, and my QF redemption (on CX) has my QFF number on it).

Does anyone know how to update the FF number online to a partner? I am VA Gold, and would like to add it to the SQ booking for increased baggage & I’ll probably grab a status match to AB Gold to get increased baggage on my QF/CX booking.

Neither QFF nor KF logins will allow me to change my FF number away from their programs online.

Thoughts? Experiences? Ideas?

Easiest way is to do this during check in. Otherwise, you will have to ring up.