Originally Posted by jadenus

I don't think the booking class needs to be the same to do a SDC....

Originally Posted by CO Insider

Hi Everyone, when it comes to the availability for same-day confirmed changes within 12 hours of departure, it's a question of whether the flight is available (i.e. booked below capacity) rather than fare class. In simplest terms, we'll always offer the confirmed option within 12 hours of departure when the main cabin is booked below actual capacity. In these cases, we'll open up all main cabin fare classes at the 12-hour mark, enabling confirmed same-day changes regardless of fare class. On the other hand, when the main cabin is booked at or above capacity, the flight will be unavailable in most or all main cabin fare classes....