Originally Posted by
Alex Whittingham
AFAIK rudestuff is correct, its an ICAO requirement to have ATPL theory credits to fly multi-crew over 5700kg that first the UK, then the JAA and EASA have adopted. Not the case in all jurisdictions, maybe not in SA for instance.
Just to be sure, by "to fly multi-crew" you mean CS-25 aircraft.
You should still be able to fly in multi-crew environment on aircraft that are CS-23 with CPL+MCC (no ATPL theory), IIRC.
Correct me if I am wrong.