Children must normally use a child car seat until they're 12 years old or 135 centimetres tall, whichever comes first. Children over 12 or more than 135cm tall must wear a seat belt. You can choose a child car seat based on your child's height or weight.

Group 0+ - 0kg up to 13kg (newborn up to around 15 months) Group 1 - 9kg up to 18kg (newborn up to around 4-years-old) Group 2 - 15kg up to 25kg (from around 9 months up to around 6-years-old) Group 3 - 22kg up to 36kg (from around 4-years-old up to 12-years-old)

While 1 year and 20 pounds used to be the standard for when to flip car seats around, most experts now recommend using rear-facing child seats until children outgrow the top weight and height recommendations of the car seat manufacturer. This means your child may be rear-facing until well beyond their second birthday.