Our writers test and research products independently. When you buy through a link on our site we may earn a commission but this never affects our product choices.
Whether you're gearing up for some long family road trips or tend to transfer your sleeping baby in their infant car seat from the car to the pushchair, it's worth knowing that research suggests the safest sleep position for newborns is lying flat on their backs. This insight has prompted leading car seat manufacturers to design lie-flat car seats that either semi or fully recline, and that can be used from birth until your little one reaches around 13kg.
The lie-flat position isn't just a comfier choice. It offers babies a more natural sleeping posture, which allows for easier breathing and prevents slumping in their car seat. Plus, it's kinder on their spines and hips, reducing the risk of hip issues down the road.
Now, don't get us wrong - traditional upright car seats are perfectly safe and meet legal car seat safety requirements in the UK (children should use car seats until they're 12 years old or 135cm tall). However, experts generally advise not keeping babies in an upright car seat for more than two hours at a stretch. Newborns should be taken out of their car seat every 30 minutes.
That's where lie-flat car seats step in, offering a comfy and more ergonomic option for longer car journeys. Some can even transform into carrycots with a mattress for sleeping both in and out of the car.
How we chose the best lie-flat car seats
We began our in-depth research by collating the tried and tested experiences of Mumsnet parents on our forums, home to around 8 million users per month.
We analysed countless consumer reviews on retail sites.
We made sure that every one of our recommended lie-flat car seats had been independently tested and awarded safety scores from the German automobile club ADAC, which performs stringent safety tests.
Some of the lie-flat car seats on our list have also been awarded top safety scores from Stiftung Warentest (the German consumer organisation that tests and rates products, including car seats) and ÖAMTC, Austria's largest automobile club, which conducts evaluations of automotive and safety products.
Best lie-flat car seats at a glance
Best overall lie-flat car seat
What we like
Offers plenty of safety features
Doesn’t take up too much space in your car
Easy and intuitive to install
Simple to wipe clean
What we don't like
Heavy to carry
ISOFIX base sold separately
Doesn’t lay completely flat
Price: £195 | Age range: 0+; Birth to 12-15 months or approx. 85cm | i-Size: Yes | Weight: 5.2kg | Dimensions: 65 x 44 x 57.5cm | Installation: Three-point safety harness and ISOFIX | Travel system-compatible: Yes | ADAC test: Good (1.7) | Warranty: 2 years
What Mumsnet users say
Designed to meet the tough i-Size regulations (R129), the Joie Signature i-Level Recline is a rearward-facing seat that offers a deep, cosy recline position at 157 degrees for your little one.
As part of the Joie Signature range, this car seat boasts more luxurious features than those in its standard range, with its vegan leather detailing on the harness padding, removable sun canopy that can be unzipped and extended further, plus a sturdy, no-slip leather handle for easy carrying.
The Joie Signature i-Level Recline comes with plenty of impressive safety features which is why we think it deserves the best overall lie-flat car seat rating. In addition to its enhanced side impact protection features, this lie-flat car seat has multiple layers of memory foam that offer a good amount of cushioning.
In addition, the load leg enhances stability by reducing forward rotation, and the TriProtect headrest (consisting of three layers of special materials that absorb energy during a crash) has seven adjustable heights to ensure your child fits securely as they grow. The ‘Good’ ADAC rating also highlights how simple it is to adjust the height of the harness straps with a central adjuster button.
The seat can only be installed using a base like the i-Base Encore (sold separately) via the ISOFIX connectors in your car. Although the base is sold separately, it is compatible with at least four other Joie car seats, thus offering a more longevity as your child grows.
Read next: The best umbrella stroller and pushchairs
Best value lie-flat car seat
What we like
‘Very good’ ADAC rating
Lies completely flat
Easy to use
Available in five colours
Compatible with several other bases and pushchairs
What we don't like
Only lasts until six months or 9kg
Heavier than other lie-flat car seats
ISOFIX base sold separately
Price: £169 | Age range: 0+; Birth to six months or approx. 9 kg | i-Size: Yes | Weight: 5.9kg | Dimensions: 80.5 x 47.5 x 34 cm | Installation: Three-point safety harness and ISOFIX with 3way Fix Base | Travel system-compatible: Yes | ADAC test: Very good (1.5) | Warranty: 2 years
What Mumsnet users say
Introduced in 2019, the Maxi-Cosi Jade was the first i-Size certified carrycot-style car seat to be approved on the market and, since then, it’s become a firm favourite amongst parents. It ticks all the safety boxes, having been awarded a ‘Very good’ ADAC rating, and offers supreme comfort on long car journeys without putting too much of a dent in your pocket.
Like the other lie-flat car seats on our list, this model securely attaches to a base, allowing your little one to lie flat at a 180-degree angle, which addresses the challenge of extended car journeys lasting more than two hours. Several bases are compatible with this lie-flat car seat including the Maxi-Cosi FamilyFix3 or FamilyFix2 so be sure to check for compatibility.
Thanks to the simple Slide & Go ISOFIX installation, this car seat is a breeze to secure into place as it slides onto the base that's already attached to the car's ISOFIX connectors, showing you if it’s fitted correctly with light and colour indicators.
Safety features include an adjustable three-point safety harness, lateral positioning in the car for optimal front and side protection, and full sun protection with a cover and hood, so your newborn will stay snug and secure both in and out of the car.
The only downside? This car seat takes up a lot of space in the backseat and is only suitable for use from birth until your baby reaches 70cm in height, which could be as early as six months old. However, it’s compatible with a variety of Maxi-Cosi pushchairs, including the Maxi-Cosi Adorra.
Read next: The best double buggies
Best compact lie-flat car seat
What we like
180-degree rotation for easy boarding
Includes load leg for extra safety
Can be used from birth to two years
Comes with a newborn inlay
What we don't like
It doesn’t lie completely flat in the car
Price doesn’t include the Z2 base, but you can find both as part of a bundle
Price: £199 | Age range: 0+; Birth to 18-24 months or approx. 87cm | i-Size: Yes | Weight: 4.6kg | Dimensions: 65 x 44 x 38 - 60cm | Installation: Three-point safety harness and ISOFIX or with seat belt only | Travel system-compatible: Yes | ADAC test: Good (1.8) | Warranty: 2 years
What Mumsnet users say
As one of the lightest and slimmest lie-flat car seats on our list, you may assume that the Cybex Cloud Z2 i-Size isn’t as safe as bulkier car seats on the market. But the truth is, this newer Cybex model meets the strictest safety criteria, including the ECE-R129 (i-Size) standard, and it’s been awarded top safety certifications by ADAC, Stiftung Warentest and ÖAMTC respectively.
This lie-flat car seat is also very easy to install thanks to clear visual guides to help you click it onto the ISOFIX base, or the green belt guides to help you thread the seat belt on either side of the seat. The load leg releases quickly and is fixed to the floor in minutes, plus the adaptable headrest provides 12 different positions to perfectly tailor the fit as your child grows. Additionally, the built-in harness guide simplifies and speeds up the adjustment process to ensure a perfect and safe fit.
Once installed, one of the Cybex Cloud Z2’s main safety features includes its Linear Side-Impact Protection (LSP) system designed to enhance safety by absorbing and dissipating the energy from a side-impact collision in a controlled manner, utilising the built-in shoulder and head protectors.
While most car seats in the 0+ age category can only be used until 12 to 15 months of age, this car seat is suitable up to the age of 18 to 24 months, offering more usage in the long run. Plus, it has a nifty swivel function, allowing you to get your child out of the car with ease.
Thanks to the adapters, you can easily attach the Cloud Z2 i-Size car seat to a Cybex pushchair or other compatible brand. You’ll also find Cybex’s latest car seat, the Cybex Cloud T i-Size, available to buy, which is a newer version of the Cloud Z2 but not yet tested by the likes of the ADAC.
Read next: The best 360 spin car seats
Best convertible lie-flat car seat
Jané Matrix Light 2
What we like
Fits into any car
Easy to carry
Compatible with a variety of Jané pushchairs
What we don't like
Pricey (ISOFIX base sold separately)
Seat is bulkier than other lie-flat seats
Price: £349 | Age range: 0+; Birth to 18 months or approx. 13kg (lie flat until 10kg) | i-Size: Yes | Weight: 5.25kg | Dimensions: 83 x 44 x 62cm | Installation: Five-point safety harness and ISOFIX or with seat belt only | Travel system-compatible: Yes | ADAC test: Satisfying (2.8) | Warranty: 2 years
What Mumsnet users say
If you’re looking for a spacious lie-flat car seat for your newborn that works just as well as a carrycot – and therefore has no time limit for longer car journeys (when used with a Jané mattress, sold separately) - then the award-winning Jané Matrix 2 is a good choice.
Not only has the Jané Matrix Light 2 met all UK infant car seat safety standards, but another stand-out feature is how easily it converts from a car seat to a carrycot and back again – with the simple click of a button.
Plus, it boasts an impressive 180-degree lie-flat position compared to the semi lie-flat positions of other car seats, which allows your little one to snooze peacefully both in and out of the car. Mumsnetters agree that it’s good value for money as it’s compatible with a variety of Jané pushchairs, offering you a complete travel system for your growing baby.
From an installation point of view, the Jané Matrix Light 2 fits safely onto the ISOFIX swivel base that rotates towards you, making it easier to manoeuvre this seat in and out of the car. Or if you’re switching the car seat between cars, simply secure it with the five-point harness system designed with durable, longer straps to secure it tightly in a sideways position.
One thing to bear in mind is that the lie-flat position takes up quite a bit of space in the backseat whether secured with or without ISOFIX as it needs two seat belts that are guided through clips on either side of the seat.
Once your child reaches 10+kg, this roomy carrycot converts to an upright car seat designed with a patented Pro-Fix system that locks and unlocks the car seat with just one movement. With four backrest positions plus an automatic height adjustment for the shoulder pads, this lie-flat car seat has ample space to grow with your child.
Read next: The best pram toys for babies
Best lightweight lie-flat car seat
What we like
Weighs under 4kg (is easy to carry)
Removable sun canopy with breathable mesh window
Comes with merino wool infant insert
What we don't like
Base sold separately
Price: £250 | Age range: 0+; Birth to 15 months or approx. 13kg | i-Size: Yes | Weight: 3.5kg (not including canopy and insert) | Dimensions: 64-77 x 43 x 59cm | Installation: Three-point safety harness and ISOFIX | Travel system-compatible: Yes | ADAC test: Good (1.8) | Warranty: 2 years
What Mumsnet users say
With its renowned reputation for producing high-quality, innovative child safety products including car seats, Dutch company Nuna is trusted for meeting the highest safety standards with its award-winning ARRA Next lie-flat car seat that boasts the latest ECE-R129 (i-Size) standard and has achieved a ‘Good’ rating from ADAC. This model has also won the notable Red Dot Product Design Award in 2020, which is only given to products that demonstrate exceptional design quality and innovation.
When it comes to design, the Nuna ARRA Next car seat has three convenient reclining positions and can lie at 157 degrees, making it comfortable for your little one on longer car rides. Its ISOFIX base (sold separately) has a 360-degree swivel function and it’s part of the complete Nuna Mixx Next travel system, offering four car seat options for the first four years. Plus, it can also fit into a variety of other travel systems, with adapters.
Weighing in at only 3.5kg, this lie-flat car seat is the lightest on our list and a good choice if you’re regularly transferring your car seat from the car to the pushchair and back. However, it does weigh a little more (approximately 3.9kg) with the infant insert and sun canopy attached.
We like that the Nuna ARRA Next is simple to install and secure onto the base thanks to the five-second, True lock™ base installation system with coloured indicators to confirm when it’s been fitted correctly. It’s also no sweat to secure your child into the seat with the adjustable three-point safety harness, with plenty of room to grow with your child.
Another great feature is the durable shell around the centre of the seat, which has an energy-absorbing layer, along with fixed side impact protection components, which together provide exceptional protection in the event of an accident. Other notable features include a 10-position adjustable and removable headrest that's made with patented Tailor tech memory foam, a high-strength handle that transfers a large portion of the crash forces into the shell, and a stability leg that makes the car seat feel even more secure in the back.
The Nuna Arra Next is also the only car seat on our list to hold the prestigious GREENGUARD Gold Certification, signifying its adherence to the strictest third-party chemical emissions standards. In a nutshell, this guarantees your child's safety without compromising indoor air quality.
What is a lie-flat car seat?
A lie-flat car seat, also known as a lie-flat infant car seat or carrycot car seat, is a specialised type of car seat designed to provide a safe and comfortable reclined position for newborns and infants during car journeys. Unlike traditional upright car seats, which keep babies in a semi-upright or upright position, lie-flat car seats allow babies to lie flat on their backs.
This position mimics the recommended sleeping posture for infants and offers several benefits, including better support for your baby's spine and hips, improved breathing and reduced risk of hip dysplasia.
Lie-flat car seats are suitable from birth and are particularly beneficial for longer car rides, where infants can rest comfortably while ensuring their safety during travel. Some lie-flat car seats like the Jané Matrix Light 2 can even convert into a carrycot, providing a safe sleeping environment outside the car.
Is it worth getting a lie-flat car seat?
The decision to invest in a lie-flat car seat depends on various factors, including your baby's age, the duration of your car journeys and your peace of mind. Car seats that enable your baby to sleep flat usually cater for babies up to 75cm or around 12 to 13 months old.
While traditional upright car seats are considered safe and meet legal requirements in the UK, there are essential considerations that might sway your choice in favour of a lie-flat car seat.
Firstly, the two-hour car seat rule is often cited by healthcare professionals and safety experts. It recommends that infants shouldn't remain in an upright car seat for more than two hours at a stretch. This guideline is based on concerns about potential breathing and comfort issues that can arise when babies are seated in a semi-upright position for extended periods.
In 2016, a study took place at the Great Western Hospitals NHS Foundation Trust with additional support from the University of Bristol. This research team looked into how car journeys affect infants. What they found was that little ones born prematurely or at a tender age might be at risk of some breathing difficulties if they're seated upright in car seats at a 40-degree angle for long stretches.
Lie-flat car seats address this concern by allowing your baby to recline in a more natural, comfortable sleeping posture. This position helps keep their airways clear and supports the proper alignment of their spine and hips. Additionally, lie-flat car seats are particularly beneficial for longer journeys, as they enable your baby to nap and rest comfortably while ensuring their safety during travel.
Ultimately, whether you need a lie-flat car seat depends on your specific circumstances. If you go on extended car trips with your newborn or prefer the added reassurance of a more natural sleeping position, a lie-flat car seat could be a valuable investment. However, for shorter journeys, a traditional upright car seat that complies with safety regulations may suffice.
What age do babies not need to lie flat?
Babies typically no longer need to lie flat in a fully reclined position when they can sit up independently, which typically occurs between five and seven months of age.
However, it's important to note that the exact timing can vary from one baby to another, so it's essential to observe your baby's developmental milestones and consult with your paediatrician for guidance on when it's safe to transition to a more upright position in a lightweight stroller or car seat. The transition should be gradual and based on your baby's individual readiness.
When it comes to the safest sleeping position for newborns, the NHS, says it’s best for babies to sleep flat on their backs for the first six months, or until they can sit up on their own.
What is i-Size?
According to the NHS, i-Size is a European car seat safety standard under ECE R129 that aims to replace the older R44/04 regulation with stricter safety standards in time. However, currently both are available to buy and legal to use in the UK.
Some key features that make a car seat i-Size compliant include:
Rear-facing installation: i-Size car seats in the 0+ category are typically installed in a rear-facing position, which is considered safer for infants and young children.
ISOFIX compatibility: i-Size car seats require ISOFIX connectors, which provide a secure and standardised attachment to the car's chassis, reducing the risk of installation errors.
Side-impact protection: i-Size car seats have enhanced side-impact protection to minimise injury risk in side collisions.
Height-based sizing: i-Size seats are categorised based on your child's height rather than weight, ensuring a better fit and improved safety as your child grows.
Top tether or load leg: Many i-Size car seats include a top tether or support leg for added stability and safety.
Standardised testing: i-Size seats undergo rigorous standardised testing to meet safety criteria, including crash tests and performance assessments.
Universal compatibility: i-Size seats are designed to fit in all i-Size-approved vehicles, enhancing compatibility across different car models.
Easier installation: The standardised design of i-Size seats and ISOFIX connectors simplifies the installation process, reducing the risk of errors.
What are the differences between R44 and R129 car seats?
As detailed in our best toddler car seats guide, i-Size seats will replace all R44 seats in time. But at the moment, here are the key differences between them:
Classification is based on weight
While side-impact tests aren’t mandatory, certain manufacturers still choose to conduct them
Testing for frontal collisions is performed at a velocity of 50km/h, while rear-impact collision tests are carried out at 30km/h
The seat can be installed using either a seat belt or ISOFIX connectors
The seat must remain rear-facing until the child reaches 9kg (approximately nine months of age)
Categorisation relies on height measurements
Side-impact evaluations are compulsory
Only ISOFIX installation is allowed
The seat should remain rear facing until the child is around 15 months
All seats have side-impact protection, which typically involves cushioning around the headrest and sides to absorb impact forces during a car accident, thus preventing severe head injuries
How to choose the best lie-flat car seat
When selecting the best lie-flat car seat for your baby, consider the following factors:
Safety first: Make sure the car seat meets the latest safety regulations, like the R44 and/or i-Size standard (ECE R129) and has undergone thorough crash testing.
Age and weight suitability: Check if the car seat is suitable for your child's age and weight. Some lie-flat seats work from birth, while others have varying weight limits.
Easy installation: Ensure the car seat can be easily and securely installed in your vehicle. Some use ISOFIX connectors, while others, like the Jané Matrix Light 2, use both the ISOFIX and/or seat belts.
Flexible recline: A good lie-flat car seat should typically recline to an angle of between 130 to 180 degree or as close to flat as possible. This position allows for a safe and comfortable sleeping posture for newborns and young infants while travelling in the car.
Side-impact protection: For added safety, consider seats with enhanced side-impact protection, like reinforced sides or impact-absorbing materials.
Vehicle compatibility: Check if the car seat fits well in your specific vehicle, especially if you have a unique car model and more than one car seat to fit in the back.
User-friendly features: Look for a car seat with convenient features like an adjustable harness, one-handed recline adjustment and simple installation instructions.
Weight and portability: Consider the seat's weight as you might need to carry it when your baby isn't in the car. Lightweight options like the Cybex Cloud Z2 i-Size can be more practical.
Travel system ready: If you plan to use your lie-flat car seat with a stroller or pram, confirm its compatibility with your chosen system. Most of the lie-flat car seats on our list come with a range of travel system options.
The padding: Assess the lie-flat car seat's padding and overall comfort to ensure your baby is well supported.
Easy to clean: Check if the lie-flat car seat’s covers and padding are removable and machine washable for hassle-free maintenance.
Budget-friendly choices: It’s always a good idea to determine your budget and explore options within your price range, keeping safety and quality in mind.
Trusted brands: Consider reputable brands known for their dedication to safety and high-quality products when making your decision. Luckily, all the lie-flat options on our list are made according to the highest safety standards.
How much should I spend on a lie-flat car seat?
The price range for lie-flat car seats can vary significantly depending on the brand, features and quality. Generally, you can find lie-flat car seats ranging from £150 to £400 or even higher for premium models. The amount you should spend on a lie-flat car seat depends on your specific needs, preferences and budget.
When choosing which one to buy, it’s wise not to compromise on the safety features, but do think about how long you plan to use the car seat. For instance, some lie-flat car seats like the Cybex Cloud Z2 i-Size are suitable from birth to a higher weight/age limit, potentially providing a longer useful life.
Can you use a secondhand lie-flat car seat?
As the NHS and car seat safety expert, Jan James, from Good Egg Car Safety advises, it’s best to avoid purchasing secondhand lie-flat car seats as they might be damaged, missing parts, lack instructions and could be incompatible with your car.
About the author
Tammy Jacks has 15+ years' experience in the publishing industry, enjoying a long and fruitful career as Managing Editor and Health & Beauty Editor for Woman & Home magazine in South Africa. She later went on to become Assistant Editor of the popular South African parenting title Living and Loving, and has written for numerous lifestyle publications including Oprah Mag SA, Health Intelligence, Your Family Magazine, Longevity, and pharmaceutical company Clicks Clubcard Magazine, as well as edited books for popular fitness influencers and health professionals.
Tammy is a distinguished researcher and writer in the field of child safety, with a notable focus on the critical domain of car seats. Her extensive expertise and commitment to child safety have made her a trusted authority in providing comprehensive insights and guidance to parents and caregivers looking for the right car seat for their children. As a mum to an eight-year-old, Tammy has personally tried and tested numerous car seats over the years, across all age categories.
About the editor
Laura Westerman is an editor, writer and Deputy Head of Editorial Content at Mumsnet. With over seven years' experience as a full-time editor, five of which have been spent writing, commissioning and editing car seat product reviews and round-ups, Laura has a keen eye for what parents love and likes nothing more than putting together honest reviews to make parents' lives that little bit easier.
In addition to her work as a writer and editor, she has also appeared in a number of baby product review videos for Mumsnet's YouTube channel. She is mum to a one-year-old.
Why you should trust us
We work hard to provide honest and independent advice you can trust and we spend hours scouring the Mumsnet forums and online bestseller lists to find products that real parents rate.
Transparency is really important to us and that's why we're always upfront about where we find our recommendations. We write about products that we feel offer the best value to most parents – the ones that our users would recommend to their own friends and family.