What Is An i-size Car Seat?

Introduced in 2013, i-size is a type-approval category sitting within the latest R129 UN Regulation, which governs car seat safety standard. The i-size classification means that the car seat is compatible with i-size positions in vehicles and has been developed to deliver enhanced safety and security. Although no date has been released, it is envisaged that the R129 will replace the R44 standard at some point in the future. The i-size is often referred to in the name of the product but is also identifiable by an orange R129 label. 

What are the key features of the i-size?

i-size for greater impact protection

Greater impact protection - i-size car seats are tested more rigorously to include side-impact testing, in addition to the existing front and rear tests. Increased sensitivity in the crash test dummies has led to greater protection in the event of a collision.

i-size for correct installation

Reduced chance of incorrect installation: it’s said up to 70% of car seats installed using the vehicle’s seat belt are not fitted correctly. i-size seats are fitted using Isofix anchor points, which greatly reduces the risk of incorrect installation.

i-size for rear-facing

Young babies stay safer for longer: Young babies do not have sufficient muscle strength to protect their neck in the event of a collision, so to prevent injuries keep them rear-facing for as long as possible; i-size car seats make this mandatory to 15 months old.

i-size for a better fit

Designed for the individual: As the size of babies can greatly differ, the i-size seats are classified by the child’s height rather than weight, ensuring they’re rear-facing until at least 15 months old.

Top tips for purchasing an i-size 

i-size buying tips


Prior to making the purchase it is worthwhile verifying a few details. First, do check the compatibility of the car seat you like with your main vehicle, as well as any cars you may regularly use. Simply contact the retailer and supply the make, model, and age of your car/s so that they can check the vehicle fitting list. Do also ask if the car seat is supplied with a user manual as you will need to carefully refer to this when using your car seat. For reassurance, do double check that your child fits within the stated size limits, and finally do look out for the distinctive orange sticker, stating the product adheres to R129 standards. 

Introducing Ickle Bubba’s Mercury i-size car seat

Here at Ickle Bubba our goal is to ensure you feel confident in purchasing your next car seat, and to remove any guesswork from the equation. An i-size car seat is a fantastic and superior option in terms of safety performance, as well as offering your new born the ultimate in front, rear and side protection. The Mercury i-Size and Isofix base are the perfect duo for your bubba’s car journeys, and can be fitted to our travel systems


The Mercury also leads the way in comfort with its 6-point adjustable head rest, newborn memory foam insert, integrated vents for air flow, UPF 50 hood as well as its soft, breathable, and removable covers.

Should you wish to check if the Mercury is compatible with your car please do contact Team Bubba.

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