When do you start to use booster seat with your child?

Typically a booster seat is meant for children ages four to eight (or 19kg to 36kg). Depending on the development on your child, you can decide when is a good time to use it. One of my colleagues started using a booster seat for her daughter when her girl was five and couldn't fit into her car seat (but has yet to reach 1.35m in height).