Child safety in the car - a guide to child car seats

Most car accidents happen close to home. Child car seats can keep your child safe. But not every seat fits every car. And if a seat is fiddly to use, you may be tempted not bother with it on short journeys. Here are our top tips for choosing the best car seat for your child.

Understanding car seats

There are two different types of car seat:

  • Group (0-III) is based on the weight and physical development of the child.

Age ranges are given too, but these are just for guidance. 

  • i-Size is based on the child’s height and seats provide protection from side impacts.

They fit all i-Size-ready cars and some ISOFIX cars.

As not all i-Size seats fit ISOFIX cars, we advise checking if the seat is approved for your car before you buy one.

Baby car seats

It’s safest for babies to travel rear-facing for as long as possible. 

Rear-facing seats are either:

  • Group 0+ (Group 0 seats are no longer readily available)
  • i-Size.

Don’t be tempted to move a baby to a forward-facing seat just because their feet are pressing against the rear seat of your car.

It’s best to wait until they reach the weight limit or the crown of their head reaches the top of the baby seat.

Always travel with your baby in the back seat if you can.

If it’s essential for them to be in the front seat, the passenger airbag must be switched off - if the airbag activates in a crash it will harm your baby.

Remember, child car seats aren’t intended to be places for babies to sleep when you’re not travelling, so move them to a moses basket or cot as soon as you can.

Car seats for toddlers and young children

When your baby has outgrown their baby car seat they can be moved to a child seat with a built-in harness.

These seats are mostly forward-facing, but some rear-facing seats are now available.

The group to look for is: 

  • Group I.

Forward-facing i-Size seats will become available in future.

It’s safest to keep your child in a car seat with an integral harness for as long as possible.

Only move your child from a car seat to a booster seat when their eye-line is above the back of the child seat or the weight limit is reached.

Older children and car seats 

Most booster seats ‘grow’ with your child.

Booster seats suitable for children who weigh between 15kg and 36kg are: 

  • Group II
  • Group III

A high-backed booster seat offers the best protection for your child, providing side protection and support.

Remember, adult seat belts don’t sit on children’s bodies in the right places and can injure them in a car accident.

Buying your baby or child car seat

Buying second-hand car seats is not recommended.

They may have been damaged in an accident, but you won’t necessarily be able to tell by looking at them.

If you do use a second-hand car seat, try to make sure you know its history and read the manufacturer’s instructions. Check nothing’s damaged and no parts are missing.

Not every seat will fit properly in every car. Try the seat in your car before you buy it, or check the returns policy.

Make sure the seat can be fitted exactly to the manufacturer’s instructions.

The seat should be secure. If it wobbles, it is either wrongly fitted or not suitable for your car.

If your car has ISOFIX attachments, consider buying an ISOFIX seat.

Try to find a seat that’s quick and easy to fit into your car. If it’s awkward, it may be tempting to not bother with it on short journeys.

It’s vital you use your child car seat on every journey - most accidents happen within a short distance of home. 

Make sure the seat you buy fits on the back seat as this is safer for your child.

A quick guide to kids’ car seat rules

The law applies to cars, vans and other goods vehicles.

Children under three years old

You must always use a child restraint appropriate for the child’s age, height and weight, whether the child is travelling in the front or rear of the vehicle.

If an appropriate restraint is not available, it’s illegal for a child to travel in the vehicle.

The only exception is in a taxi if the correct child restraint isn’t available.

Children aged between three and 11 years old

You must use an appropriate child restraint for the child’s age, height and weight in the front seat and, if seat belts are fitted, in the rear seat.

The only exceptions to this are where the correct child restraint is not available in the following situations:

  • In a taxi where the correct child restraint is not available
  • For reason of unexpected necessity over a short distance
  • Two occupied child restraints prevent a third from being fitted.

In these cases, an adult seat belt must be used.

Children more than 135cm in height or 12 years old and over

An adult seat belt must be worn if fitted.


More information

Find out about cycle safety and teaching road safety.

Download the Department for Transport’s booklet on seat belts and child restraints.