When can a car seat be turned forward-facing?

This depends on the type of car seat and the safety standard it follows.

ECE R44 car seats

Children must remain rear-facing until they weigh at least 9 kg (20 lbs).

ECE R129 car seats

Children must remain rear-facing until at least 15 months of age.

Even though these are the minimum requirements, safety experts recommend that children remain rear-facing for as long as possible.

In practice, this often means keeping the seat rear-facing until at least 4 years of age, or until the child no longer fits in the rear-facing seat.