Answer: Hi,
From my understanding this depends on the make and model of the individual child restraint which is being used. Some are designed to face the back until 12 months and others for longer. Please check out the link below which is very specific about recommendations. Also consider your baby’s weight and height, these are important factors to optimise safety. Read the manufacturer’s recommendations about the individual car seat you have, they will be very specific about what’s safe or not. If in doubt, ring their help-line or check them out on line.
You are doing the right thing by investigating this information.
Cheers
Jane

http://www.vicroads.vic.gov.au/Home/SafetyAndRules/SaferVehicles/ChildRestraints/ChooseTheRightChildRestraint.htm