When choosing a child car seat it’s important to get it right. Here’s our simple guide to choosing a seat that’s perfect for your family and the cars you drive.

What does the law say?

In the UK all children under 135cm tall or younger than 12 years old must use a child restraint appropriate for their weight in any vehicle, including vans and other goods vehicles. Parents who do not comply with the law risk fines of up to £500.

Rules around children’s car seats have changed a lot over the past decade to make them even safer, so never be guided by what your parents did.

All seats must be EU-approved to the latest standards. Seats that make the grade can be identified by the orange ‘Approved’ label, which carries the code R129. This signifies that it is a safe and suitable seat to buy.

Your child’s weight, not age, will determine which seat to use. European regulations* set out eight categories of seat scaled according to weight range.  

Child’s weight



0kg to 10kg


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 25kg


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

22kg to 36kg


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

Should you use a rear- or front-facing seat?

Use a rear-facing model until your baby weighs 9kg/20lbs and can sit unsupported. You can then change to a front-facing seat. Rear-facing baby seats must not be used in a seat protected by a frontal airbag unless the airbag has been deactivated.

What about booster seats?

New regulations were introduced in February 2017 to improve road safety for smaller children. They stopped manufacturers producing backless booster seats for children shorter than 125cm or weighing less than 22kg, because seats with backs offer better side impact protection.

But models that are already on the market can continue to be sold and any existing seats you own can still be used in accordance with government guidelines, provided they have the standard safety mark ECE R44.

Is there a right seat for your car?

The seat may need to fit more than one car. You’ll need to make sure that the seat is suitable for all.

Although many child car seats are described as ‘universal’ it does not mean they will fit in all cars. It simply means that they can be fitted with seatbelts or have the anchorage points to be fixed in cars with Isofix fittings.

All cars produced after 2011 are equipped with Isofix fixed points within a vehicle’s seats that can be used to attach your child’s car seat.

If you have an older car you can check with the manufacturer, consult the vehicle manual or look for the thick staple-shaped metal fittings between the back and bottom of the seat.

To choose a child seat that will suit all the cars in your family you’ll also need consider the curve and angle of the seats in the cars. It’s a good idea to check compatibility with the retailer or manufacturer before you buy.

The most expensive seat isn’t necessarily the safest. Check and compare online reviews to help you make your final choice. Users will give feedback on usability, ease of handling, practicality and fitting. 

Fitting a child’s car seat

Many manufacturers provide videos that show how to fit their child car seats. Retailers often have trained staff who can help demonstrate fitting, so ask about a demonstration before you buy.

Always keep and follow the manufacturer’s instructions and don’t hesitate to contact them if you are having problems.

Practise before putting a child into the seat for the first time, and make sure that the seat is fitted as tightly as possible with no excessive forward or sideways movement.

The safest place for a child to travel is in the middle of the back seat, which is likely to be furthest from any impact.

Can you use a second hand child car seat?

It’s not worth the risk. Older seats might not comply with the latest safety regulations. They might not be adequately tested, and they might be missing the instruction booklet that tells you how to install and adjust the seat safely.

There can be invisible damage to the structure through general wear and tear, or deterioration in the strapping if strong cleaners have been used. If a car seat has been in an accident, however minor, there could be invisible damage that compromises the protection the seat will give in the future.

* European regulations on weight-based child car seats (https://www.gov.uk/child-car-seats-the-rules)