Car Seat Regulations

Children’s car seats aren’t just a nice thing to have, they are a legal necessity with car seat law stating children should be in an appropriately sized seat until they’re 135cm in height (150cm in ROI) or 12 years old, whichever comes first.

That’s why a car seat is one of the biggest investments you'll make in your child's safety, and it's only natural that you want to make sure you're making the right choice.

Getting to grips with all the car seat advice out there can feel like a bit of a minefield, so to help make it easier, we've broken down some key considerations for you.

What is a child car seat?

Children’s car seats are designed to get younger kids from A to B safely and comfortably. As car seats, seatbelts and safety equipment like airbags are designed with adults in mind from both ergonomic and safety perspectives, child safety seats are needed to give children the same level of comfort as adults and often improved safety. Car seats are made from a mixture of robust materials, with impact-absorbing foams and comfortable, child-friendly fabrics usually mounted to a sturdy frame.

Shop child car seats

Can I take my child in a car without a car seat?

The short answer is no. Any child up to either 12 years old or 135cm/150cm in ROI (whichever comes first) must be seated in a suitable car seat on every journey, no matter how short it is, how busy the road is, or where they’re sitting in the car. This golden rule isn’t just a guideline either – you can be fined for breaking the law.

How do I choose the right car seat?

Choosing the right child car seat may seem complicated at first, but it’s easier once you get your head around the two sizing systems.

R44 (weight-based) seats

The first sizing system is weight-based and is defined by the UK’s R44 legislation. These size groups are defined by a child’s weight, so you can simply pick a car seat that matches how much they weigh, and some seats are designed to span multiple groups. Here’s a breakdown of the R44 sizing groups:

Group Child's Weight Age of Child
0 Birth up to 10kg (22lbs) Birth to 6 or 9 months
0+ Birth up to 13kg (29lbs) Birth to 12 to 15 months
0+ &1 Birth up to 18kg (40lbs) Birth to 4 years 
1 9- 19kg (20-40lbs) 9 months to 4 years
1 & 2 9- 25kg (20-55lbs) 9 months to 6 years
2 15 - 25 kg (33- 55lbs) 4 years to 6 years
1, 2, & 3 9 -36 kg (20-79lbs) 9 months to 6 years
2 & 3 15- 36 kg (33lbs - 79 lbs) 4 years to 12 years

i-Size car seats are the next option. i-Size seats conform to EU safety legislation R129, which will eventually be adopted across all new car seats sold. i-Size seats are simply another option at this stage, but with a few key differences.

i-Size car seats are selected by using your child’s height. This means you’ll need to crack out the tape measure or use a chart if you have access to one – we have this available in our stores.

Another big difference with i-Size seats is that babies and infants face backwards for longer. Rear-facing car seats have been found to be safer than forward-facing seats, partly due to a lack of strength in a baby’s neck muscles. That’s why all i-Size seats are rearward facing up until 15 months old. This doesn’t mean your forward-facing group 1 seat is dangerous, however, so you don’t need to upgrade to i-Size straight away.

i-Size seats come in three different sizes, each of which has a rough equivalent within the R44 sizing system:

  • 0-85cm (approximately G0+ in weight-based system) – rear-facing baby carrier or baby seat using a harness
  • 0-105cm (approximately G0/1/2) – rear-facing baby seat until your child is at least 76cm, then forward facing
  • 100-135cm (UK)/150cm (ROI) (approximately G2/3) – forward-facing child sea

More on i-Size car seats

What is ISOFIX?

No matter which type of car seat you go for, it’ll need to be securely fastened into a vehicle. Many car seats use a seatbelt and a brace that pushes against the floor to prevent the car seat moving around, but ISOFIX differs as the child seat fastens to the frame of the car itself.

The rear seats of most new cars (produced since 2013) have a pair of anchor points. These anchor points connect to a separate ISOFIX base (often sold with the child car seat but check on the packaging or in the online description), making for an extremely strong connection. The child car seat then fastens to the ISOFIX base, so there’s no need to clip car seat belts around or through the seat or tighten braces in the car seats or floor.

All i-Size car seats are compatible with cars that have ISOFIX anchor points, but some R44/04 car seats don’t come with an ISOFIX option, so check descriptions and packaging if you want to take advantage of ISOFIX systems

More on ISOFIX car seats

What is impact shield technology?

Impact shields are one of the newest safety features available and the technology is being incorporated into an increasing number of car seats.

Otherwise known as safety cushions, impact shields fasten around the front of your child while they’re in their car seat. They act like a pre-inflated airbag and help to spread the forces generated during a collision over a wider area. This reduces the strain on key areas of the body and helps to keep your child safe during a collision.

Car seats with impact shield technology are particularly useful in cases where it’s not possible to use a rear-facing seat, as they provide an extra level of protection

More on impact shield technology

The New ECE R129 Legislation

The ECE R129 is the latest EU/UK safety standard for child car seats but what exactly does this entail? We spoke to child car seat expert, Joie to find out more about the R129 regulation and how this differs from other car seat safety standards.


What is the R129 regulation?

The ECE R129 was first introduced during 2013 and the existing ECE R44 standard was allowed to run in parallel. While R44 car seats can still currently be purchased, from the 1st September 2023, R129 will become the only approved car seat standard.

The simplest way to understand the ECE R129 regulation is that it focuses on the child’s height rather than their weight. It’s often a challenge for parents to know when they should upgrade their child’s car seat. Therefore, height can more accurately allow parents to measure if an existing car seat is the best fit for their little one rather than weight.

It's recommended that children travel rearward facing up to a minimum of 75cm (approx.15 months) as research shows that this gives them time to develop and ensure their neck is strong enough to support their head. R129 car seats also undergo further testing than other car seat standards including side impact testing and Q dummy crash tests which include 32 sensors.

What is the difference between R129 and i-Size?

While R129 car seats and i-Size car seats undergo similar safety testing, they are not the same thing. The easiest way to think of it is that i-Size is an enhancement of R129. I-Size focuses on ensuring that car seats fit safely into vehicles using ISOFIX anchor points. Therefore, while all i-Size car seats may comply with R129 standards, not all R129 car seats may be i-Size compatible. Many i-Size car seats have ‘i’ at the beginning of the product name or you can look out for the i-Size logo.

What is the difference between R129 and R44?

The key differences between the R129 and R44 standards are as follows:

  • ECE R129 focuses on the child’s height in cm, while the ECE R44 focuses on a child’s weight in kg
  • R129 is not categorised into groups, while R44 is categorised into groups 0+,1,2,3
  • Children must be rear-facing to a minimum of 75cm or 15 months with R129, while a child can be forward facing from 9KG with R144
  • R129 has additional side impact testing, while R44 is only rear and front tested
  • R129 conducts Q dummy crash tests with 32 sensors, while R44 conducts P dummy crash tests with 4 sensors

What also makes R129 unique is that the standard is divided into four categories, covering different child sizes, seat installation and how the child is secured within the child restraint system (CRS).

Can I still buy R44 car seats?

R44 car seats can currently still be purchased and are still subject to extensive testing despite being gradually phased out. Joie confirms that these are still reliable car seats and are safe to use. From 1st September 2023, authorities will no longer accept approvals for R44 car seats and from 1st September 2024, they will no longer be sold by retailers, marketplaces and e-commerce in the EU/UK. This means that businesses will have one year to sell any remaining R44 car sets they have in stock.

It's important to understand that customers can still use an R44 car seat that has been purchased after 1st September 2023.

What types of R129 car seats can I buy?

Joie stock a wide range of child car seats that are ECE R129 compliant and will continue to launch new R129 car seats over the coming year. ECE R44 car seats will continue to be available until they are eventually phased out.

With R129 car seats no longer using group numbers, Joie have categorised their car seats using the following:

  • Baby car seat (up to approx. 12 months)
  • Toddler car seat (up to approx. 4 years)
  • Child car seats (up to approx.12 years with internal harness and seat belt)
  • Belted booster seat (approx. 3-12 years with seat belt)
  • Spinning car seat (all spinning car seats)

Check out our full range of Joie R129 car seats and have the peace of mind that your child is travelling both safely and comfortably

Joie R129 car seats

Car seats at Halfords

Hopefully, you now feel a bit more clued up. However, we have lots of fully trained, RoSPA-accredited staff members throughout our store who will be more than happy to guide you through this big decision.

To make it really easy for you to choose the right car seat for your little one, we have also broken down all the features of our car seat range into the following categories:


Simply look out for these icons when choosing your car seat to ensure you're getting all the features that are important to you.

If you’re still unsure and would prefer to talk this through with one of our experts, contact us on Live Chat where we can offer more advice.

All child car seats

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