How to Choose the Right Car Seat

As well as purchasing key newborn items like a buggy or crib, a baby car seat is an essential item to get ready for your little one’s arrival. As your child grows, you will also need to choose the right car seat for their weight and height, so knowing how to choose the best car seat for your family will depend on a few things.

Children’s car seats are essential for your child to travel safely and are a legal requirement to have the right car seat appropriately fitted up until they are 12 years old or 135cm – whichever comes first.

Kids car seats explained

Whether it’s your first car seat purchase, or you’re looking for a next-step car seat as your child grows, we have shared some advice to help you choose the right car seat for your children. For further guidance on all things Autocare, check out the HiQ Help and Advice Section.[DB(U1]

If you need help identifying which type of car seat to buy, you will first need to select which seat is appropriate based on your child’s height or weight, as decided by UK Safety Regulations, also referred to as group numbers.

In the UK, car seat group numbers include:

• Group 0: 0-10kg (approx. birth to 6-9 months)
• Group 0+: 0-13kg (approx. birth to 12-15 months)
• Group 1: 9-18 kg (approx. 9 months to 4 years)
• Group 2: 15-25 kg (approx. 4-6 years)
• Group 3: 22-36 kg (approx. 6-11 years)

Each car seat will be able to accommodate children suitable to the group number identified. Some more advanced car seats can adapt as your child grows and will be able to accommodate a range of groups using an all-in-one car seat. These car seats will need to be manually adapted by you as your child reaches the next suitable group stage, to keep your child car seat in line with safety legislation.

Car seat rules for UK children

By law, all children must be in an appropriately sized car seat until they are 135cm (4ft 5in) tall or 12-years-old, whichever comes first.

Rules on children’s car seats in the UK [DB(U2] currently conform to two approved safety standards based around the two sizing systems.

• R44 – this is the original safety standard using ‘groups’ as detailed above.
• R129 – this is a higher safety standard that was introduced from July 2013 and includes i-Size car seats.

As of September 2024, R129 will become the only Legal Regulation for car seats in the UK, replacing R44. More information on rules around these two types of guidance for car seats is covered below.

i-Size car seats

i-Size car seats are available in the UK and conform to EU safety legislation R129, which will eventually be adopted across all new car seats. R44 style car seats in circulation are still completely safe to buy, but will simply be phased out to conform to R129 legislation.

At this stage, the i-Size car seat system is simply another option in the UK, with a few key differences to consider when choosing the right car seat for you.

• i-Size car seats are selected by using your child’s height.
• i-Size car seats are rearward facing up until 15 months old, to support your babies’ neck for longer.
• i-Size car seats come in three different sizes, (0-85cm / 0-105cm / 100 – 135cm) which have a rough equivalent within the R44 sizing system, but are based on height alone.

Isofix car seat

When choosing the right car seat for your child and car, you should also consider how it will be securely fastened, such as:

• Using the cars lap and diagonal seat belt only
• Using your car’s ISOFIX secure click-in system

ISOFIX uses two anchoring points built into the base of your car's seats and is considered safer due to the click-in installation process, which does not have to be removed, unlike a car seat belt. However, not all cars have ISOFIX, so you will need to check your car manufacturers’ guide to choose the right car seat in accordance with your car’s requirements.

• i-Size car seats are only compatible with cars that have ISOFIX
• Some R44/04 car seats don’t come with an ISOFIX option, so will be suitable for non ISOFIX suitable cars.

Car seats for infants

Also referred to as a baby car seat, infant car seats are designed for newborns, are lightweight with carry handles, and are essential for coming home from the hospital.

• Group 0
• Child height: 40-85cm
• Birth up to 12-15 months
• Weight: birth up to 13kg/29l

Be aware, it's illegal to use a rear-facing car seat in the front passenger seat if there is an active airbag. It's also very dangerous even if it's a forward-facing car seat, so it’s always best to keep children in the back seat if possible.

Car seats for toddlers

Once your baby out grows a rear-facing car seat, forward facing car seats are the ideal solution for toddlers. Be aware, forward-facing car seats are not designed to be carried.

• Group 0+ & 1
• Child height: 40-105cm
• Birth up to 4 years
• Weight: birth up to 18kg/40lb

Combination car seats, or multi-group car seats, can be adjusted as your child grows. Forward-facing car seats will suit children up to approximately age 4, or around 18kg, by adjusting the harness and head rest as your child grows.

Car seats for children

Car seats for older children are still necessary, up until they reach 135cm or age 12, whichever comes first. These car seats are usually called booster seats, which are light weight and easy to fit.

• Group 2 & 3
• Child height: 100-150cm
• Approximate age: Approx 4-12 years
• Child weight: 15-36kg/33-79lb

To find out more about choosing and using the correct car seat for your child, The Child Car Seats website has up-to-date and UK GOV approved information on child travel safety.