At a glance
- Age range: Approximately three-and-a-half to 12 years; 100 to 150cm in height
- Safety credentials: Complies with ECE R129/03; Side Protection System Plus (SPS)
- Fixing system: Seatbelt and ISOFIX or three-point seatbelt only
- Dimensions: 51 × 44 × 76cm
- Weight: 5.9kg
- Guarantee: Lifetime warranty
- RRP: £189
- Easy to install
- Simple headrest adjustment
- Width of the seat increases with the height of the headrest
- Open design makes it easy for your child to get in and out
- Good-quality look and feel
- ISOFIX connectors stiff to use at first
- Only available in plain colours
- Conforms to R129 car seat regulations
- Fits any car with ISOFIX
- Quick and easy to install and buckle up
- SPS – side impact-absorbing material added to each side wing
- Adjustable backrest for both height and width so genuinely grows with your child
How safe is the Maxi-Cosi Kore i-Size?
This Maxi-Cosi Kore i-Size is packed full of safety features to keep your child safe on every journey. The seat conforms to R129/03 which classifies car seat size based on a child’s height, rather than weight. This means that it has also undergone side impact testing as well as rear and front.
In addition, the Kore i-Size has Side Protection System Plus which uses improved impact-absorbing materials in each side wing to reduce the risk of injury in the event of a side collision. The seat also has glass fibre shock absorbers for maximum safety and its cocoon shell means it provides full-body protection.
As with all high back booster seats, a child is secured in the Maxi-Cosi Kore i-Size using the car’s three-point seatbelt – there is no integral harness as you'd find on baby car seats.
Clear instructions and green seatbelt guides give a good indication of the correct placement and position of the seatbelt across the lap and chest, providing reassurance that a child is safe and secure at all times.
Our tester, Jemma, thought it would be very difficult to make a mistake when installing this seat, even in a hurry, as belt routing was generally very intuitive.
The car seat felt secure when fitted with ISOFIX and seatbelt together, with or without a child in the seat. Using the seatbelt fitting only, the car seat felt secure with a child in the seat but, without, there was some 'give'. With that said, it didn't move around inside the car.
For stability, it is recommended that parents with ISOFIX-ready cars always use ISOFIX when installing the Maxi-Cosi Kore i-Size.
When it comes to design, there are no loose parts that could potentially be swallowed or anywhere for curious little fingers to get trapped.
That said, Jemma did think the ISOFIX installation was a little fiddly.
What’s the difference between the Maxi-Cosi Kore i-Size and Maxi-Cosi Kore Pro i-Size?
In addition to the Kore, Jemma also tested the Kore Pro, which is part of the Kore family and has a retail price of £219.
It has all the safety credentials of the Kore, but comes with additional features, such as a ClickAssist light. This light illuminates the seatbelt socket for 30 seconds when a child gets into the seat, making it easier for them to buckle themselves in.
Jemma found this feature really useful, especially when she had all three of her car seats installed in her car, as it really helped her and her five-year-old daughter to locate the socket.
The Kore Pro i-Size is also made from premium bamboo fabrics (the regular Kore is made from polyester) that have cooling properties, which helps a child to stay cool in the seat even when the weather is warm.
Jemma loved the look of the seat and thought the fabric was lovely. The cover was easy to remove, wash and replace and looked and felt premium in quality.
On balance, however, while she appreciated these features, she didn’t think she would choose this version of the seat over the standard Kore – the extra features wouldn’t be enough to tempt her to spend an additional £30.
How easy is the Maxi-Cosi Kore i-Size to install?
Maxi-Cosi's Kore i-Size is incredibly easy to install. Everything you need for set-up is included in the box and the instruction manual contains clear, easy-to-follow illustrations plus details on altering the seat to suit different-sized children. Jemma also tested the seat with her four- and seven-year-old nieces.
Installation was completed in a matter of minutes, with the ISOFIX and seatbelt installation taking a little longer than the seatbelt fitting alone.
The instruction manual indicates on which seats in a five-seater car the Kore i-Size can be used, and directed Jemma to a website for checking installation in particular cars. Here it was clear that she could use the Kore i-Size in all the seats in the middle row of her seven-seater Citroën Grand C4 Picasso, as well as in both seats in the rear row.
She found it fuss-free to move the Kore between the rows where necessary, and there was nothing at all about the seat that was distracting for the driver – no matter where it was positioned in the car.
If using ISOFIX, you simply pull out the connectors in the bottom of the seat and click them into place. Jemma found the ISOFIX connectors a little stiff and fiddly to use at first, but these became smoother once the seat had been used a few times.
You then use the seatbelt to further secure the seat and your child into the car. The seatbelt routing is clear and easy to follow, which is reassuring for parents who may feel that they need some extra guidance.
If your car doesn’t have ISOFIX, then you can secure the Kore i-Size using the vehicle's three-point seatbelt. The illustrations in the installation guide show exactly where across your child's shoulder and lap the seatbelt should be sitting.
The headrest is simple to adjust one-handed once the seat has been installed in the car – the adjuster is located at the side of the headrest to make this easier. This meant that Jemma felt confident that her daughter and nieces were positioned correctly in the seat during every journey.
Although there is a designated pocket in the seat for storing the instruction manual, if you do lose the paper copy you can download another from Maxi-Cosi’s website.
There’s a wealth of useful information on the website, including how to register your car seat and apply for the warranty, and details on what to do if your seat has a defect. There are also customer service contact details on the website, including a UK phone number.
Maxi-Cosi also offers the SWAP service, offering advice and help if your child is involved in an accident while in their Max-Cosi car seat.
What’s it like to use day-to-day?
Jemma found the Maxi-Cosi Kore i-Size really easy and convenient to use on a day-to-day basis. Her daughter, who was almost six at the time of testing, was able to climb easily in and out of the seat and was very comfortable, even on longer journeys of approximately an hour in length.
The seat is easy to adjust if needed (for an older or younger sibling, for example). Both the headrest and the seat width can be altered to suit all ages and heights within the designated range, which means that the seat is always the correct size no matter the child.
During testing, the headrest had well-fitting height settings for Jemma's daughter and nieces. She was particularly pleased when it came to her four-year-old niece who she noted as being tall for her age.
The Kore i-Size was used on the daily school run as well as on longer journeys. Even when in a rush, Jemma found the seat simple and convenient to use. Her daughter could also climb in and out of the seat easily and could do up the seatbelt herself, which made life easier and allowed for more independence.
Jemma felt confident that her daughter was secured properly, even when using the seatbelt on her own, as it was easy to buckle up. Do be aware though that, if using the seat in the middle of a row between other car seats, this isn’t so easy (and likely not possible) for a younger child to accomplish as the gaps between the seats are too narrow.
All-in-all the Kore i-Size is stress-free and a breeze to use day-to-day. It's also relatively lightweight at just under 6kg, so could be taken on holiday and could be used in a taxi if needed.
How does it look?
It can be tricky to find the right high back booster once your child graduates from their toddler car seat. Lasting from pre-school all the way up to secondary school, what appeals to your four-year-old won't necessarily still appeal when reach age 12.
When faced with this dilemma, the Kore i-Size ticks all the boxes. The simple design and plain colours that may seem limiting when your child is small will ensure that the seat looks sleek and stylish as they start to feel more grown up. It’s a seat that should appeal across the age group.
Jemma’s daughter liked the seat, and Jemma thought the seat was sleeker than other child car seats she tested, including the attractive Britax Römer Kidfix III M. It was one of her favourites in terms of appearance. She also felt the fabric was good quality and her child found the seat comfortable against the skin.
The Kore i-Size boasts five neutral colourways, which most parents will enjoy. The colours are: Authentic Black, Authentic Graphite, Authentic Grey, Authentic Cognac, and Authentic Red. We tested the Authentic Black.
How easy is it to clean?
Maxi-Cosi's darker colour options means that the Kore i-Size has the ability to hide a multitude of child-induced stains – but, of course, it will still need to be washed, especially if you opt for the lightest shade (Authentic Grey).
The seat can be surface-washed with a damp cloth and the covers can be removed for machine washing at 30 degrees.
While car seat covers are often tricky to remove, with the shape changing substantially after washing, Maxi-Cosi has offered some light relief. The Kore's covers washed well during testing, with stains coming out easily in the first wash. They were also surprisingly easy to put back on thanks to a good system of tabs.
Jemma commented after washing that the seat looked as good as new and also reported no wear and tear.
What about value for money?
With an RRP of £189, the Maxi-Cosi Kore i-Size wasn't the cheapest seat we tested, but not the most expensive either.
As a seat that will appeal to most ages, which is definitely something to take into account when deciding on the right car seat for you and your family, overall the Kore offers good longevity for a very reasonable price tag.
While it only offers one additional accessory, you can purchase a back seat protector for £20, which will help to protect your car’s interior.
We love the simplicity and the price of the Kore i-Size, which is why it pipped Maxi-Cosi's latest version, the Kore Pro, to the post during testing.
The fact that the seat conforms to the new R129 safety regulations is a big plus – the only other seat to do this was the more expensive BeSafe iZi Flex Fix i-Size, which retails at £249.
Not only is the Kore i-Size simple to install, but it looks great, washes well, and has been manufactured by a brand that parents know they can trust. The lifetime warranty is simply the icing on the cake, which is why it's Mumsnet's Best Child Seat 2020.
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All prices correct at time of publication