Using a child car seat or booster seat

Children must use a child car seat until they're 12 years old or 135cm tall, whichever comes first.

Only EU-approved child car seats can be used in the UK. These have a label showing a capital ‘E’ in a circle.

You can choose a child car seat based on your child’s height or weight.

Height-based car seats

Height-based car seats are known as ‘i-Size’ seats. They must be rear-facing until your child is over 15 months old. Your child can use a forward-facing car seat when they’re over 15 months old.

You must check the seat to make sure it’s suitable for the height of your child.

Weight-based car seats

The seat your child can use (and the way they must be restrained in it) depends on their weight.

You may be able to choose from more than one type of seat.

Child's weight and appropriate car seat

0kg to 9kg - Lie-flat or ‘lateral’ baby carrier, rear-facing baby carrier, or rear-facing baby seat using a harness

0kg to 13kg - Rear-facing baby carrier or rear-facing baby seat using a harness

9kg to 18kg - Rear or forward-facing baby seat using a harness or safety shield

15kg to 36kg - Rear or forward-facing child seat (high-backed booster seat or booster cushion) using a seat belt, harness or safety shield

Fitting a child car seat

You must only use a child car seat if your car’s seat belt has a diagonal strap, unless the car seat is either:

  • specifically designed for use with a lap seat belt

  • fitted using ISOFIX anchor points

You must also:

  • deactivate any front airbags before fitting a rear-facing baby seat in a front seat

  • not fit a child car seat in side-facing seats

Useful links

More information about the child car seats and the law (opens in new window)

Good Egg safety (opens in new window)

Last updated: Wednesday 18 January 2023

Related images

Firefighter checks that a childs car seat is fitted correctly