What is i-size?

All car seats are approved to a regulation, meaning they must pass certain tests before they can go on sale. 

Child car seats are grouped either on according to your child's weight or your child's height. They are not selected according to your child's age. 

The new European standard for child car seats, known as i-size forms part of the UN regulation ECE R129. 

The idea behind i-size is that all car seats will eventually fit in all cars. Your car and your seat must have isofix, a fitting system that attaches the car seat directly to the frame of your car using isofixconnectors. At the moment, even of your car has anchor points, an isofix car seat wont necessarily fit. I-size aims to change this.  

More and more cars that come onto the market should be i-size ready. However, at the moment there are very few available. For now, you can buy an i-size seat, but you'll need to check the list of approved vehicles that fit the seat and check the fitting in your car. 

 One of the big improvements that R129/i-size should bring about is a reduced risk of fitting your child's car seat incorrectly. Generally, isofix seats are simpler to fit than ones that use the vehicles seat belts. 


Another key benefit of R129/i-size is the introduction of side impact crash testing as part of the approval process. Child car seats approved to R44/04 regulation do not have to pass the a side impact crash test in order to be sold, even though so many on the market claim to have added 'side impact protection'. 


i-size car seats also make it mandatory to rear face until 15months old.