How to choose a car seat for a baby, toddler or child

Smiling woman strapping her happy toddler into her car's child seat

Choosing a child seat for your car can be confusing. The law often changes, as it did with the recent revision over the use of backless booster seats. There seem to be as many different brands and models as there are cars on the road. And trying to determine the differences between categories or groups of seat, while checking whether one seat or another is compatible with your car, can be almost as tiring as caring for a newborn baby.

Then there’s the tricky task of fitting a seat correctly. Last summer, a spot check of 100 drivers with children in the vehicle revealed that 32 seats were not installed correctly. One in 10 of those were deemed dangerous.

Clearly, drivers find this a difficult area to navigate. So here’s what to consider when choosing a car seat for a baby, toddler or child. And we’ve included an overview of the laws and penalties governing child seat use.


Why it’s important to use a child seat in a car

Children are vulnerable in car crashes. Their bones are soft, they have comparatively heavy heads and weak necks, and their internal organs are more susceptible to injury caused by sudden deceleration. That’s why the law is in place to do the utmost to protect children in car crashes.

Child car seat laws in the UK

The most important starting point when buying a child seat is the law. In the UK, this states that children must use a child car seat until they’re 12-years old or 135cm tall, whichever comes first.

Responsibility falls to the driver. Whether you’re ferrying your children in their car seats or giving a friend’s child a lift, the driver can be penalised if any laws are broken.

Police can issue drivers with a fixed penalty notice of £100 for failing to follow child seat law. The one exemption is if there is an unforeseen emergency. In this case, children aged three and over are allowed to travel in the rear seat using a seat belt for a short distance.

Understanding car seat groups

Whether buying your first car seat for a newborn baby, or picking a replacement seat for a fast-growing six-year old, you need to check the car seat groups.

These groups are defined by the United Nations safety regulations. In the UK they span from newborns to those who are 12-years old, 135cm in height or taller, or weigh more than 36kg.

They fall into two categories: height-based seats, and weight-based seats.

Height-based seats are known as i-Size seats. They must be rear-facing until a child is at least 15-months old because it’s the safest set-up in an accident. Once the child is more than 15-months old, parents should check that any seat is suitable for the height of the child.

Weight-based seats fall into five categories (we warned you this can be confusing). Those are 0, 0+, 1, 2 and 3, with 0 being baby carriers for 0kg to 10kg infants, and 3 suited to children from 22kg to 36kg. You can see details of the child seat groups by weight here.

What is Isofix and should I buy a car seat without it?

Introduced in 1997, Isofix is a system that secures a child seat far more effectively than a seat belt. It uses a pair of locking arms that latch to special retaining bars built into the car. Compared to using a seatbelt to fix a seat, Isofix is more secure and generally considered easier to fit. There’s also less chance of it working loose in an accident.

Do your homework and don’t put it off until the last minute

Rear-facing child seat for babies up to 15-months old
Rear-facing baby seat for children up to 15-months old

There’s no quick way to choose the best car seat for your needs. That’s because not all seats fit all cars. Suitability will depend as much on the car you own, or may be buying, as it will on the height or weight of the child.

After browsing reviews of seats, check the child seat manufacturers’ websites. These will detail the cars that a seat is compatible with. And remember: if you’ll be using the seat in more than one car – such as a grandparent’s or child minder’s – find out the make, model and year of the vehicle to ensure the seat is equally suited to it.

Look for convenience features

Did you know that some car seats can adapt to accommodate growing children? Or that others can be rotated to face the door, which makes lifting kids in or out less of a back strain? For older children, features such as cupholders or speakers for a music playing device could be desirable, depending on your budget.

And finally… try before you buy

It’s important to get hands-on with a child seat. You need to know for certain how comfortable it is for your child. You should also be sure that it fits your car and know how its features work. High street stores offer the opportunity to do all this. However, you may need to book an appointment (which is complimentary) with a qualified fitter.

When was your car last treated to a health check? Find a garage for a safety inspection


James Mills

James is a motoring journalist and former magazine editor at BBC Top Gear and Auto Express. He has scooped, reported on and reviewed most new cars of the past 20 years, and currently contributes to the Driving section of The Sunday Times.