Once your child has outgrown their toddler car seat, they will be ready for a booster car seat, which typically lasts from ages 3 or 4 until age 12. You'll often seen these referred to as group 2/3 ...
Children must be restrained by a seat belt until the age of 18, which used to be 16 ... the latest research-based recommendations on car seat, booster seat and seat belt use for children ...