ISOFIX is a system for easy anchoring of child seats that connects the child seat firmly and easily to the vehicle body.

ISOFIX is an internationally standardized system for securing a child seat in a car, compliant with the international standard ISO 13216. Today, it is a mandatory component of passive safety used in the transportation of small children.

The ISOFIX system creates a firm connection between the child car seat and the vehicle’s body, reducing the risk of injury to the child in the seat. The connection between the child seat and the body is established using rigid anchors that latch onto prepared points on the car’s body. The advantage of the ISOFIX system lies in its ease of use, reliability, and, most importantly, the secure attachment of the seat to the vehicle. The ISOFIX anchorage points are typically located at the edges of the rear seats.


ISOFIX system connection diagram

The name ISOFIX is derived from two parts, ISO from the International Organization for Standardization and FIX from the English word fixation, meaning attachment.

Child car seats are divided into several categories, and with respect to their placement in the vehicle and ISOFIX system, two methods are crucial:

1/ Group 0 and 0+ / 0-13 kg / 0-12 months
cs_isofix_008Car seats for infants in the 0-13 kg category are preferably placed rear-facing with the child. In the event of a collision, the moving child’s energy is absorbed by the entire back surface, including the head. In simple terms, the child’s body has nowhere to go in the event of a frontal impact. Since, especially in small children, the size and weight of the head are disproportionate to the body, this reversed position prevents dangerous neck injuries.

To allow the use of the ISOFIX system for infant seats (shells, capsules, eggs), a connecting bar is usually used located in the front under the child’s feet. To enhance the stability of the child car seat, it may be equipped with an adjustable support leg.

It is recommended to place the seat on the rear, hence safer, seat. The seat can also be placed in the front, but the airbag must always be turned off!!! An active airbag is deadly for a child!

2/ Group I (9-18 kg / 9 months – 4 years) + Group II (15 – 25kg / 4 – 6 years)cs_isofix_009
Car seats for older children are placed in the vehicle facing forward. In the Czech Republic, even a small child can be placed in a child car seat in the front passenger seat. Some vehicles are equipped with specific ISOFIX anchor points for this purpose. However, remember that the passenger’s airbag is designed for an adult male model. The speed and geometry of the impact are optimized for this scenario. A child in the seat sits a bit higher and closer than an adult male, so the airbag could potentially cause harm to the child