Child Car Seat Rules

 Making your car child-proof can be tricky. They’re constantly growing, and finding the right car seat can be a difficult task. We’ve taken a look at child car seat laws, citing UK child car seat rules to make sure you’ve perfectly set up your little one before your next drive.

💺 The law on when a child needs a car seat

💺 Choosing a car seat

💺 Height-based car seats

💺 Weight-based car seats

💺 The best car seats on the market

💺 Looking for more information

The Law On When A Child Needs A Car Seat

All children under the age of 12 years old or shorter than 135cm must use a car seat. There are no exceptions to this rule, and failing to secure a child in a suitable car seat is seen as against the law. For children over the age of 12, or taller than 135cm tall, they don’t need a car seat but must wear a seat belt.

Choosing A Car Seat

Actually finding the right car seat can be tricky. You need to combine safety with comfort to ensure your child has a safe but comfortable journey.

There are two ways you can go about picking a car seat:

• Height-based.
• Weight-based.

Let’s take a look at each one in more detail.

Height-Based Car Seats

Height-based car seats are also known as ‘i-size’ seats, and have different rules based on how old you are.

For children under 15 months old, height-based seats must be rear-facing.

After 15 months, you can place the seat as forward-facing but must make sure the seat matches the child height wise. This can be tricky as a child grows, but it’s absolutely essential to ensure their safety when in the car.

Always check the height of the chair is suitable for the child, and don’t be afraid to consult a store member or online chat function when shopping to help with your request.

Legally, all height-based seats must be EU-compliant. You can tell if an ‘i-size’ seat is compliant by looking for an ‘E’ in a circle, alongside a code reading ‘R129’.

Weight-Based Car Seats

You can also choose to find a car seat by weight.

With weight-based seats, there are set child seat car groups that you must be aware of:

• Children weighing 0kg to 10kg must use either a lie-flat, lateral baby carrier, rear-facing baby carrier or rear-facing baby seat using a harness.
• Children in the 0kg to 13kg range must have a rear-facing baby carrier or rear-facing baby seat using a harness.
• Those weighing 9kg to 18kg need to be in a rear or forward-facing child car seat that uses a harness or safety shield.
• For children weighing 15kg to 25kg, you must keep them in a rear or forward-facing child car seat (high-backed booster seat or booster cushion), using a seat belt, harness, or safety shield.
• The final category is 22kg to 36kg. In this group, you must provide a rear or forward-facing child car seat (high-backed booster seat or booster cushion) using a seat belt, harness or safety shield.

To use an EU-approved weight-based car seat in the UK, it needs to have a label showing ‘E’ in a circle and ‘ECE R44’.

The Best Car Seats On The Market

According to the Telegraph, here are the best car seats in 2025:

• Best overall – Silver Cross Motion All Size 360
• Best value car seat - Graco SlimFit R129 All-in-One
• Best 360 car seat – Cybex Sirona T
• Best newborn car seat – Joie i-Level Recline
• Best booster seat – Cosatto All-in-All Rotate

Looking For More Information?

That’s the legal basis covered, but what about everyday issues, like how to choose and fit a seat?

Child Car Seats provides plenty of guides and purchasing tips for those looking to get hold of a child car seat.

This guide aims to set out the law around child car seats, but there’s plenty of more information you should consult before purchasing a car seat. Visit the government website and child seat websites to ensure you have all bases covered before purchasing a child car seat.

We’ve looked at the best cars for people with families in a separate piece. Looking for the perfect wheels to accompany your new child seat? Click here.

Sources:

https://www.gov.uk/child-car-seats-the-rules

https://www.childcarseats.org.uk/  

https://www.telegraph.co.uk/recommended/kids/best-car-seat/