i-Size car seat, i-Size certification, i-Size safety
a guaranteed back seat fit
i-Size gives you a guaranteed back seat fit in i-Size vehicles
THE SMARTER WAY TO RIDE

ask for i-Size

Choosing the safest car seat doesn't have to be complicated...when you buy an i-Size certified car seat that meets the highest ECE R129 safety standard, you're investing in a seat that offers a guaranteed fit in i-Size approved vehicles, has an intuitive installation, and is is tested by the most current European car seat standards.

i-Size is an enhancement of ECE R129

Many of Joie's car seats meet the newest and most advanced car seat regulation in the UK and EU, ECE R129. Even more of our seats have gone on to receive the additional i-Size certification to confirm a guaranteed back seat fit in an i-Size seating position. Did you know when you buy i-Size, you're also getting all of ECE R129's safety and convenience features to make your rides safer and smarter?
Tap an icon to learn more!
side impact certified icon
side impact certified
rearward facing longer icon
rearward facing longer
smartest dummies icon
smartest dummies
better fit formula icon
better fit formula
i-Size certification icon
i-Size certification
side impact certification is part of ECE R129

side impact certified

Ensures the best head, neck, and all over protection with standardised side impact testing. Older standards, like ECE R44, did not include side impact!
FACING THE FACTS
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While many of Joie's car seats have included side impact testing over the years, prior to ECE R129, side impact testing was not a requirement to pass EU standards. It is known that side impact can be the most harmful to a child and is most damaging to a baby’s head versus any other part of their body. For this reason, the ECE R129 standard is enforcing mandatory side-impact performance criteria industry-wide.
mandatory rear-facing until 76cm or 15 months is part of ECE R129

rearward facing longer

Mandates rearward-facing to a minimum of 76 cm and >15 months - which allows baby’s neck to develop and strengthen before switching to forward-facing travel.
FACING THE FACTS
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The most crashes and the most severe crashes happen at the front of the vehicle. When forward facing, children move forward during a crash — causing strain on the neck. Facing rearward manages the force of a crash, protecting developing little necks and spines up to 5 times more than forward facing. The ECE R129 testing standard requires children to stay rear facing until at least 76cm and 15 months, and we advocate for as long as possible!
ECE R129 uses the most advanced crash testing dummies with 32 sensors

smartest dummies

ECE R129 testing uses all new, advanced technology crash test dummies with more sensors than older dummies - to better simulate a child’s fragile body more accurately.
FACING THE FACTS
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ECE R129 makes use of the most high-tech crash test dummies available, called “Q” dummies. Not only has the sensory technology improved to test for greater sensitivity, the dummies also feature more sensors on fragile areas of the body. This equals a better understanding of what happens multi-directionally during a crash, allowing improved design of car seats. The older “P" newborn dummies were made only of fabric and had no sensors. The new “Q” newborn dummies now feature 32 sensors in critical locations: the head, neck, thorax and pelvis. These sensors are extremely delicate, designed to simulate the fragility of a newborn body.
ECE R129 recommends car seats by height instead of weight

better fit formula

Regulation ECE R129 determines cars seat usage based on a child’s height & weight, rather than just weight alone – ensuring a more accurate fit for growing children.
FACING THE FACTS
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Now parents can easily measure their child as an indicator when they are ready to move into the next seat. Ensure weight is also checked as most seats do still have an upper weight capacity that must still be adhered to.
i-Size is an enhancement of ECE R129 for a better back seat fit

i-Size certification

i-Size is an enhancement of ECE R129, and offers a guaranteed fit in i-Size approved vehicles thanks to stricter sizing requirements.
FACING THE FACTS
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i-Size is an enhancement of ECE R129, not a safety standard. This makes it easier to confirm your car seat’s compatibility, as any i-Size seat will fit within any vehicle with i-Size approved seating positions without the need to check compatibility fitting lists – reducing the risk of installing your car seat incorrectly primarily through the use of ISOFIX installation.
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ride with confidence.

ride with

confidence.

ride with “i”.

To ensure you're purchasing a car seat that meets the highest ECE R129 safety standard and has i-Size certification, simply look for the "i" in front of any of our car seat names (Ex: i-Prodigi™). You can also check the specifications section on our website product pages to confirm i-Size and ECE R129 certification.
*The only car seat that is an exception to this rule is spin 360™️ GTi, which is both ECE R129 regulated and i-Size certified.
You can feel confident that an i-Size car seat will fit perfectly in your back seat
What's the difference between ECE R129 or i-Size

ECE R129 or i-Size…

what's the difference?

It's common to think ECE R129 and i-Size mean the same thing because many brands and publishers have used the terms interchangeably. Including us!
While ECE R129 and i-Size car seats undergo the same side-impact testing with advanced crash-test dummies, require mandatory rear-facing until 76 cm and 15 months, and use height instead of weight for proper usage; the terms differ in two key areas:
ECE R129 safety icon

ECE R129

European safety regulation
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1. ECE R129 refers to the most recent and safest European safety regulation that controls the manufacturing of car seas. The ECE R129 safety regulation provides better side-impact protection, requires rear-facing for longer, and makes it easier to find the best-fitting car seats for your child.
i-size safety icon

i-Size

enhancement of ECE R129
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2. i-Size, on the other hand, is an enhancement of ECE R129 that makes it easier to confirm your i-Size car seat's compatibility with any i-Size approved vehicle - reducing the risk of installing your car seat incorrectly. The idea behind i-Size is that all car seats will eventually fit in all cars. While all i-Size car seats meet ECE R129 testing standards, not every ECE R129 car seat is an automatic fit for vehicles with i-Size compatible seating positions.
For extra peace of mind when shopping for a car seat, ask for a car seat that meets the ECE R129 safety regulation. For simplicity, look for the yellow i-Size icon to verify that it's suitable for your i-Size approved vehicle without the need to check the fitting list. Still have questions? Check out our FAQ section below!

how i-Size fits in

Let's see how i-Size compares to ECE R129 and ECE R44.
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Car seat safety standards chart

meet our R129 + i-Size car seats

  1.  I level recline in light gray facing a right angle on the I base encore.
    Joie signature
    i-Level™ Recline
    i-Size recline car seat for birth to 15 months
    from £150.00
  2.  Joie I-Spin 360 spinning car seat in black at an angle.
    i-Spin 360™
    i-Size Spinning car seat for birth to 4 years
    from £250.00
  3. Black I-Trillo high back booster seat facing to the right at a 45 degree angle with the headrest in the lowest position.
    i-Trillo™
    i-Size belted booster seat
    from £75.00

ECE R129 & i-Size Q&A

Like all parents, we know you are focused on keeping your child as safe as possible. We also know you might have so many questions and so little time to research. Read on below for answers to some of your more complex questions about ECE R129 and i-Size

What is ECE R129?

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ECE R129 is the new EU standard for car seat safety that was ratified in July 2013. ECE R129 has been running parallel to the older testing standard, ECE R44/04, since then. ECE R129 will replace ECE R44 entirely as the only approved EU car seat testing standard as of September 1, 2023. Only ECE R129 car seats will be legally sold to consumers in the EU from September 2024 and onward (ECE R44 can continue to be sold in England, wales & Scotland beyond the EU 1st September 2024 sales stop date).

How will ECE R129 keep my child safer?

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ECE R129 regulations promote longer rear-facing by requiring children travel rearward up to at least 15 months. Additionally, ECE R129 has introduced the first mandatory side impact testing standard, which will improve protection of the child’s head and neck. While Joie always took the initiative to test for side impact, the new regulations will ensure standards are met industry-wide.
ECE R129 makes use of the most high-tech crash test dummies available, called “Q” dummies. Not only has the sensory technology improved to test for greater sensitivity, it also features more sensors on fragile areas of the body. This means we have a better understanding of what happens during a crash, allowing us to improve the design of our car seats.
The previous “newborn” dummies (“P” dummies) were made only of fabric and did not have sensors. The new “Q” newborn dummies now feature 32 sensors in critical locations: the head, neck, thorax and pelvis. These sensors are extremely delicate, designed to simulate the fragility of a newborn body.
Since the ECE R44 standards were established the cars we drive have changed dramatically, and so has our knowledge about what happens during an accident. ECE R129 is the newest, safest standard for testing car seats. It introduces a more accurate fit for child, side-impact standards, and rearward-facing longer. ECE R129 also makes use of the latest dummy sensory technology designed to more accurately simulate a child’s fragile body. This means ECE R129 car seats are designed better, safer and stronger.

Is ECE R129 the same thing as i-Size?

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Not quite! All i-Size car seats are tested to the ECE R129 safety but not all ECE R129 car seats have i-Size certification. All i-Size car seats are tested to the ECE R129 safety standard but not all ECE R129 car seats have i-Size certification.
i-Size in an enhancement of the ECE R129 safety standard that makes it easier to confirm your car seat's compatibility in any vehicle with i-Size approved seating positions - reducing the risk of installing your car seat incorrectly. The idea behind i-Size is that all car seats will eventually fit in all cars.

Why is forward-facing not permitted until at least 15 months?

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Research shows that a baby’s neck is not yet strong enough to support their head, therefore, ECE R129 doesn’t allow forwards-facing travel until a minimum of 76cm and 15 months to ensure the child’s neck has developed the strength needed to support an average forward collision. Due to the increased security of travelling rearward or lateral-facing, many Joie car seats exceed the ECE R129 regulation and promote rearward facing up to approximately 4 years.

Why is side-impact testing and standardisation so important?

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The ECE R44 standard does not include side-impact testing, though we all know that accidents happen from all sides. While Joie has always maintained the strictest criteria for side-impact protection, the new ECE R129 standard enforces mandatory side-impact performance criteria industry-wide.

What vehicle features does i-Size require?

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Vehicles must be equipped with ISOFIX and adhere to stricter space-to-seat ratio requirements.
Check your vehicle manual to ensure that your vehicle meets i-Size regulations. In most cases, if your vehicle is equipped with ISOFIX, it may be i-Size compatible already.

Are all R129 seat i-Size?

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Not quite, change top section to - All i-Size car seats are ECE R129 certified, but not all ECE R129 certified seats are i-Size. To qualify as i-Size, the child seat must satisfy additional requirements beyond the safety testing requirements of a ECER129 certified seat.
i-Size makes for a simplified fitment method, usually ISOFIX, and assured compatibility within any i-Size approved vehicle seating position - reducing the risk of incorrect install.

Do all i-Size seats use ISOFIX for installation?

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Mostly yes, but not all. Some i-Size certified infant carriers can also fit in vehicles with the vehicle seat belt, in addition to installing with a compatible ISOFIX base, if purchased and installed.

Do ECE R129 car seats have width rescrictions like the i-Size certification?

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ECE R129 car seats have width restrictions just like i-Size, but they're slightly different. Car seats with height usage below 105cm share the same 44cm width requirement as an i-Siize car seat, however, there are other reasons why a car seat would be ECE R129 compliant but not i-Size. Within the older child car seat category (100cm-150cm), the width of ECE R129 seats is allowed to be a maximum of 52cm. Some i-Size certified car seats will naturally be this width when using their removable side impact pods, but are allowed to be classified as i-Size due to these pods being removable. And once the pods are removed, the car seat width then falls within the 44cm maximum allowance of the i-Size certification.

Can I use 3 i-Size car seats in a row on my vehicle seat?

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Most times, fitment of a belted ECE R129 car seat into the centre of the vehicle will work. However, there are instances where there is insufficient space to allow 3 car seats across if the outer two car seats are fitted using ISOFIX, so sometimes the use of 3 L104belted ECE R129 car seats to achieve this.

How can I fit 3 i-Size car seats across if my vehicle only has 2 outer i-Size seating positions?

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Most times, fitment of a belted ECE R129 car seat into the centre of the vehicle will work. However, there are instances where there is insufficient space to allow 3 car seats across if the outer two car seats are fitted using ISOFIX, so sometimes the use of 3 belted ECE R129 car seats is necessary to achieve 3-across.

Can I always use my booster seat's ISOFIX connectors if I’m fitting it into an i-Size certified seating position in the vehicle?

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Most of the time, yes! ISOFIX can be used to stabilise the booster seat on the vehicle seat while the vehicle seat belt will restrain the child. However, in some vehicles the positioning of the vehicle belt buckle will restrict the use of the ISOFIX connectors on the booster seat, but the vehicle manufacturer can still certify the seating position as i-Size, even though installation of the car seat will be much easier using the vehicle belt instead.

If ECE R129 & i-Size car seats are now height based, why is weight still important?

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Car seats still have a maximum occupant weight capacity, and this is equally as important to monitor as the primary indicator, which is the height of the child. For ISOFIX car seats, it's critical not to exceed a total weight of 33kgs, which includes the car seat AND the child occupant's weight combined. Historically, under the ECE R44 regulation, occupant weight capacity was static for group 1 car seats at 18kgs. Under the newer ECE R129 regulation, the occupant's weight capacity varies depending on the weight of the seat. For example: if a seat weighs 13kgs, the the maximum occupant weight is 20kgs. If a seat weighs 15kgs, the maximum occupan weight is 18kgs.

What has changed under Regulation ECE R129 regarding car seats installed by vehicle seat belts instead of ISOFIX?

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One big change from regulation ECE R44 is that ECE R129 belted car seats are now restricted to a single vehicle belt path per method of occupant restraint to simplify the installation and reduce user error.

Why can’t my every stage R129 face forward in the harness mode?

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Great question! Belted car seats under ECE R129 are now restricted to a single belt path per method of occupant restraint to simplify the installation and reduce user error. For multi-mode car seats like the every stage R129 that has rear-facing and forward-facing modes, there is only one belt path that can be used for harness modes and belted booster mode (formerly, there were two belt paths). The new belt path restriction that impacts the every stage R129 prioritises rearward-facing travel using the internal harness between 40-105cm. The car seat can then forward face using a simple belt path for booster mode from 100 - 145cm, and the vehicle belt becomes the primary means of restraint for both the occupant and the every stage R129 seat itself.

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