We use cookies to allow us and selected partners to improve your experience and our advertising. By continuing to browse you consent to our use of cookies. You can understand more and change your cookies preferences here.

Coronavirus Read our latest advice

Child car seat safety

Common car seat mistakes

By Alison Potter

Article 2 of 4

Despite the associated dangers, confusion over buying, fitting and using child car seats is rife. Make sure you avoid these mistakes.

Put us to the test

Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You'll instantly be able to compare our test scores, so you can make sure you don't get stuck with a Don't Buy.

Of more than 1,400 parents we questioned about child car seats in 2015, only 7% answered correctly that all children under the age of 12 – or up to 1.35m tall – must use a car seat.

Here are the other most common mistakes we've found parents make when buying and fitting a baby or child car seat:

Want to find out how child car seats performed in our crash tests? Visit our car seats reviews

1. Fitting car seats incorrectly

An important part of our car seat testing is evaluating how easy each seat is to fit and how clear the instructions and warning labels are. Our advice is to always have your car seat fit checked by an expert. But 42% of parents we surveyed in 2015 bought a new car seat without having the fit checked at all.

Even if you have had it checked, it’s a good idea to regularly re-check – have a look at our guide on how to fit child car seats.

When we asked parents about what issues they encountered with fitting car seats, the most common problem was that the car seat belt gets twisted. The second and third most common concerns were that the seat isn’t stable in the car and that the harness is not tight enough. These are things that you need to look out for when installing your car seat, as they can reduce the protection offered by a car seat in a crash.

Remember that not all car seats fit in all cars, and you should check this before you buy.

Make it simpler: download our 10 quick child car seat checks fact sheet.

2. Not knowing car seat laws and regulations

Download PDF

It’s vitally important that you know the laws governing child car seats. At best, you could be faced with a fine of up to £500, and at worst, non-compliance could be fatal.

But the regulations surrounding child car seats can be a minefield. The newer i-Size/R129 rules, first introduced in 2013, are currently running alongside the R44/04 regulations.

In fact, when we asked parents, most were unaware of the i-Size regulations. Parents with children under one are most likely to know about them, but even then it was only a 28% portion of in-the-know respondents.

Brush up on your i-Size knowledge and see the differences between the two sets of regulations with our guide to i-Size car seats.

3. Using a Don’t Buy car seat

Our tough crash tests reveal which car seats will best protect your little one in a collision. These tests are specially designed by experts to be more demanding than the legal minimum standard requires, and include both front- and side-impact tests. If a child car seat scores less than 40% in our car seat tests overall, it automatically becomes a Which? Don't Buy. 

Some car seats have scored as low as 0%. We encourage parents to make sure they know how to avoid potential safety risks by checking our list of Don't Buy car seats.

Find out more about how we test child car seats.

If you own a Don’t Buy car seat, Which? advises replacing it as soon as possible, but remember that any child car seat is better than none.

4. Using backless booster seats

Although backless booster seats meet legal requirements, Which? crash tests revealed that they offer inferior protection compared with high-backed booster seats when involved in a side-on collision. 

Our survey found that one in 10 parents believe – incorrectly – that a backless booster seat would offer the same crash protection as a high-backed booster seat, and a further 28% didn’t know.

If you use a backless booster seat, we'd advise you to change it for a full-size child seat as soon as possible. However, it is still better to use a backless booster seat than no child car seat at all.

5. Switching from rearward facing to forward facing too soon

Just over half of the respondents to our survey were not aware that it is safest for babies and small children to travel facing rearwards for as long as possible. 

The i-Size standard keeps children rearward facing until at least 15 months and cautions parents not to rush into the next seat category. 

In a frontal impact in a rear-facing seat, the child is pushed further into the seat, supporting the head and back, and limiting the movement of the head on the neck.

What I wish I'd known about buying a car seat

We asked parents to share their advice on buying a child car seat, what they learned and what they'd do differently if they were buying a car seat now. You can watch their advice in our video below.