1. Using a child car seat or booster seat

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.

Height-based seats

Height-based 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 child 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.

Only EU-approved height-based child car seats can be used in the UK. These have a label showing a capital ‘E’ in a circle and ‘R129’.

Weight-based 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 in the group for your child’s weight.

Child’s weight Group Seats
0kg to 9kg 0 Lie-flat or ‘lateral’ baby carrier, rear-facing baby carrier, or rear-facing baby seat using a harness
0kg to 13kg 0+ Rear-facing baby carrier or rear-facing baby seat using a harness
9kg to 18kg 1 Rear- or forward-facing baby seat using a harness or safety shield
15kg to 36kg 2 and 3 Rear- or forward-facing child car seat (high-backed booster seat or booster cushion) using a seat belt, harness or safety shield

Only EU-approved weight-based child car seats can be used in the UK. These have a label showing a capital ‘E’ in a circle and ‘ECE R44’.

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 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

The Child Car Seats website has information on how to choose a seat and travel safely with children in cars.

Children with disabilities or medical conditions

The same rules apply for children with disabilities or medical conditions, but they can use a disabled person’s seat belt or a child restraint designed for their needs.

A doctor can issue an exemption certificate if a child is unable to use a restraint or seat belt because of their condition.