What is the ECE R129/i-Size regulation?

ECE R129 (aka i-Size) is the most recent regulation governing the safety of car seats and is a companion to the already existing regulation ECE R44.

ECE R129 was introduced in Europe in July 2013 with the objective of heightening the safety standards for children in cars and making it easier for parents to select a car seat.

Both regulations are currently in effect and apply to the transport of children in cars from birth up to about 12 years of age (0-36 kg/40-150 cm)

The orange type approval label, which must always be present on the product, identifies the regulation that was applied when the car seat was type approved.


What is the difference between ECE R44 and ECE R129 (i-Size), and what are the main benefits of the i-Size regulation?


  • ECE R44 car seats are divided into different groups, each distinct from the other, on the basis of child weight (from 0 to 36 kg).
  • In ECE R129 (i-Size) car seats are only classified according to the height of the child (from 40 cm to 150 cm). No fixed groups exist, but the car seat manufacturer may indicate the height range within which the given car seat can be used. The adoption of the height parameter is meant to help parents select the appropriate car seat and reduce the risk of transitioning from one car seat to the next too soon. The indication of age is merely an estimate.


  • CRASH TEST: In order to receive type approval ECE R44 car seats must pass crash tests for frontal impact; besides passing frontal impact crash tests, ECE R129 car seats must also pass lateral impact testing. This test was introduced due to evidence that lateral impact crashes are the most frequent and the most dangerous for the child's head. As part of the type approval process ECE R129 car seats are tested using mannequins equipped with advanced sensors to obtain additional information about how the child's body responds to the crash.
  • REAR-FACING POSITION DURING TRAVEL: Keeping the child in the rear-facing position during travel for as long as possible is important because it reduces the risk of injury to the vertebral column. Pursuant to regulation ECE R129 children must be kept in the rear-facing position during travel until they are at least 15 months of age. This is longer than the requirement for ECE R44 car seats, which can already be used in the forward-facing position once the child weighs 9 kg. This longer time period was introduced because the rear-facing position offers the greatest safety for an infant's neck and head, since the force of impact is distributed across the whole back rather than being focused on a smaller area. The size of an infant's head is about 1/3 the size of the rest of the body, which means the muscles of the neck are incapable of supporting the weight of the head in the event of impact in the forward-facing position.


  • ECE R129 car seats are developed according to the i-Size standard making them universal and compatible with 100% of the vehicles that have i-Size compliant car seats, which are increasingly common on the market. For vehicles that do not have i-Size compliant seats consult the vehicle compatibility list provided with the car seat.