Best child car seats and high back boosters

When your child has grown out of their toddler car seat and is almost ready for school, choosing a seat that will last them up to the age of 12 may well feel impossible.

After all, how can you pick a car seat for your pre-schooler that will also see them right through to secondary school?

We've done the research and testing and narrowed down our 2021 picks to help you make that all-important choice.

How we chose the products to test

We commissioned Alison Williams to research the best child car seats on the market.

With two grown-up children, she has experienced almost all the stages of parenthood and has previously written articles on a wide range of parenting subjects, including reviews of baby car seats, toddler car seats, breast pumps and maternity pillows for Mumsnet.

Alison spent approximately 30 hours researching the UK's top seats. This included looking at crash test results and price points, scouring the Mumsnet forums to find out which seats parents were raving about, researching old favourites as well as those that were new to market and, finally, looking at which innovative designs were really making parents’ life easier.

She also checked out reliable consumer sites like Which, Honest John and Wirecutter, and studied reviews on Amazon, Feefo, Trustpilot, Uber Kids and Halfords.

Most importantly, she researched the latest safety innovations and regulations to make sure that every seat we tested and recommended reached those standards. She spoke to CO Jan James of Good Egg Car Safety and Margaret Bolt, founder of Rear-Facing Toddlers, to make sure that she thoroughly understood the latest regulations and safety advice when it came to recommending car seats.

How real-life comparative testing makes Mumsnet Reviews unique

Following the research stage, Alison then came up with a longlist of 25 car seats that were then narrowed down to a shortlist of 12 for testing with a family over a period of five months.

To do this, Alison teamed up with Jemma, a mum of three, whose five-year-old daughter used the car seats in the family’s Citroën Grand C4 Picasso. The seats were also occasionally used with her four- and seven-year-old nieces.

When testing products in a single category, we think it’s really important to work with one tester to ensure consistency in our results and to make comparison easier. We also think it’s fairer to put all the seats through the same rigorous testing process using the same children and the same day-to-day routine.

High back booster seats are often very similar so, on paper, there may not be much difference between them. Working with one tester means that those small differences – the thoughtful details that make life that little bit easier for parents and, equally, the little niggles and irritations that negatively affect day-to-day use – can be seen and experienced much more clearly.

Once testing had finished, the seats were then scored on the following criteria: safety and stability, assembly, day-to-day use, cleanliness, aesthetics and value for money. The five highest-performing products that offered the best value for most parents were awarded a Mumsnet Best badge and two others were also chosen as recommended buys.

And the results are in. Here are the seven best high back booster seats for 2021.

What are the different types of child car seats?

UK law states that all children need to be in a car seat up to the age of 12 or 135cm (whichever comes first). When buying a seat at this stage, ideally you'll want it to last until your child no longer needs one.

Child car seats fall into five groups:

1. Group 1/2/3 (R44/04) – from 9 to 36kg, or around nine months to age 12 (or 135cm)
2. Group 2 (R44/04) – suitable from 15kg to 25kg, or approximately four to six years of age
3. Group 2/3 (R44/04) – from approximately four years up to age 12 or 135cm (15 to 36kg)
4. Group 3 (R44/04) – can be used with children who weigh 22kg to 36 kg and are 125cm or taller
5. i-Size (R129) – conforming to the R129 regulation, i-Size car seats for this age group can be used from 100 to 135cm (or from 135cm to 150cm in specific cars)

What is a high back booster seat?

A high back booster is a child car seat used from approximately age three to 12. It has sides (usually well-padded) and a headrest, and it will provide routing for the shoulder and lap part of the vehicle's seatbelt.

Depending on the specific seat and the car it's fitted in, it can often be used in combination with ISOFIX fixings.

What is a backless booster seat and is it safe?

A backless booster seat is a seat cushion for children, which can be routed into the car using only the lap part of the seatbelt.

Legislation around high back booster seats and booster cushions changed in March 2017. An amendment to R44/04 means that new-to-market backless booster seats approved after this date can only be used with children weighing more than 22kg and who are taller than 125cm.

If a booster cushion was approved before this amendment, the approval relates to Group 2/3 (15 to 36kg) seats. As such, if the label on the booster cushion has a stated weight of 15kg to 36kg, it is still legal to use.

However, as Jan James from Good Egg Car Safety points out, this doesn’t mean it’s the safest option for a younger child. Booster cushions are unable to provide the side impact protection that a high back booster can. As such, it is recommend that parents use a high back booster instead.

What is i-Size?

i-Size car seats meet the new R129 European car seat safety standards that came into force in July 2013, which aims to increase the safety performance of all car seats on the market.

R129 regulations are currently running in parallel with R44 so you can buy car seats that adhere to either guidelines. At some point, R44 car seats will be phased out of the shops – but it's unclear exactly when this will happen.

What are the differences between R44 and R129?

R44

• Classification based on weight
• Rear and front impact testing
• Can be fitted using seat belt or ISOFIX points
• Seat must be rear-facing until your child weighs 9kg

R129

• Classification is based on height
• Rear, front and side-impact testing
• Seat is attached using ISOFIX points
• Seat must be rear-facing until your child is older than 15 months

How much should I spend on a car seat?

Prices vary considerably and it is worth looking into exactly what higher-priced seats are offering before spending any money as the most expensive seats aren’t necessarily the best.

Safety is the most important thing and all car seats must conform to R44 or R129 regulations. Bigger brands often conduct their own safety testing too.

So, if you’re on a tight budget, do keep safety in mind as your first priority and make sure you always check independent reviews before buying.

Can you use secondhand car seats?

A car seat's main job is to protect your child and, for that purpose, it tends to be a single-use item. You can use a car seat until you have an accident, at which point it must be thrown away and replaced.

While secondhand seats aren't necessarily unsafe, if you buy a seat from someone you don't know you have no real way of knowing the seat's history. This may not be the case if it's been passed down from a relative or a friend, but even if the seat looks fine, it could still have suffered invisible damage that has made it weak or unsafe.

As such, experts from Good Egg Car Safety recommend never buying a secondhand car seat.

Related: Read our full child car seats buyer's guide

How we tested our selection of child car seats

Our tester, Jemma, used the child car seats we tested exactly as any mum would. They were tested right from the very start – from the unpacking and assembly of the seat when it arrived to installing it into the car.

Each seat was used on the daily school run and on longer trips of up to an hour. They were also switched between cars and different-aged children before being scored on other practicalities like stain removal, washing and getting pesky covers off and back on again.

Here's what we looked at for each of the six key testing criteria.

Safety, stability and comfort

• Crash test results
• How easy was the seat to install – was there any room for error?
• Additional safety features
• Materials – are they durable and robust?
• How comfortable was the child in the seat?
• Was there anything about the seat that could distract the parent while driving?

Assembly

• Were clear instructions provided?
• Was everything needed for set-up included in the box?
• Did the seat need more than one person to install it?
• Was the seat easy to install overall?
• Were there a website and a customer service helpline if you got stuck?

Day-to-day use

• Could the child get in and out of the seat quickly and safely?
• For longevity – could the seat grow with a child?
• Was it easy to adjust the seat if you needed to use it with a child of different ages?
• Was it easy to strap your child in the seat when you were in a rush? Could they do it themselves?

Aesthetics and cleanliness

• Was the seat easy to clean? We spilled milk and juice on each seat to see how it fared after cleaning
• Were the covers removable for washing, and were they easy to put back on afterwards?
• How does the seat look overall? Is the fabric good quality? Would the seat still appeal to your child as they grow?

Value for money

• Does the seat offer good value for money?
• Does the price seem reasonable, particularly given the length of time it will be used?

Related: Read more about how we tested child car seats

Why you should trust us

All Mumsnet product reviews are written by real parents. We work hard to provide honest and independent advice you can trust – brands can’t pay to be featured in our articles or win a Mumsnet Best award.

We spend hours researching, speaking to parents, analysing data and listening to experts before we test out the products on our shortlist.

Transparency is really important to us and that's why we're always upfront about how we tested the products we recommend. We won't always recommend the cheapest products or the ones with the most extra features. We write about products that we feel offer the best value to most parents – the ones we'd recommend to our own friends and family.

We do sometimes earn revenue through affiliate (click-to-buy) links in our articles. This helps us fund more helpful and independent review pieces like this one. However, we never allow this to influence our coverage.

Our recommendations are always made entirely by our journalists without input from our commercial team, and our writers are never made aware of any business relationships.

If you decided to buy something that we recommended as a result of our research and testing, we usually (not always) get paid affiliate commission from the retailer where you make a purchase. But, if you weren't impressed with the product and decided to return it, we wouldn't make a penny.

There's no incentive for us to be lazy with our research or in our testing process. There's no reason for us to respond to pressure from retailers or brands trying to promote new products. It's actually quite the opposite and we think it's a good system, one that keeps us focused on making parents lives' easier.

All prices on this page correct at time of writing.

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