Originally Posted by
DreamHigh
I've upgraded a BR flight from Y to I before using AC miles and crediting to OZ. Flight posted normally and the cabin/fare is denoted as C/Y
This is very encouraging! Thank you for sharing! I would like to understand the process a bit more

so please bear with me.
Here is how I map out the process:
When you purchased the ticket, I would assume you keyed in your AC FFP number. And then you used AC miles to upgrade it. And then you switched the FFP number from AC to OZ. Is that correct?