how long rear facing car seat

In Australia, babies under 6 months must ride rear-facing; from 6 months to under 4 years they can be rear- or forward-facing in an approved restraint.

Best practice is to keep them rear-facing as long as they fit the seat—until they reach the seat’s rear-facing shoulder-height marker—which, in many modern 0–4 seats, is often around 2 to 4 years.

Age is a pub-story guide; height and fit are king: harness at or just below the shoulders, head contained by the shell, and no height marker breached.

If in doubt, see an authorised fitter and the seat manual—the only thing that should turn early is the car into your driveway, not the seat.