While it's the law that every child under 7 must be restrained in a proper child restraint, it's not a bad idea to use a booster seat for as long as your child will fit it, even if they're not legally required to use one.
The current recommendation in New Zealand is that children should be in a booster seat until they're 148cm tall, you may have heard the ads on the radio 'It's safer to wait until 148'. We know that's not always feasible, and we've even had a few mums and dads in the shop who aren't 148cm tall, but we still recommend it as a guide.
A lot of booster seats are made to suit up to a 12 year old child. The Recaro Milano booster seat
is a great option for an older child. It has an adjustable headrest that lets it grow with the child, and a handy seat belt latch at the shoulder to ensure that the belt is positioned at the correct position on your child's shoulder.