ISOFIX anchorages

What is the ISOFIX mounting system?

ISOFIX is an international standard (ISO 13216) that defines a standardized mounting system for child car seats. Its primary objective is to ensure simple, fast, and above all safe installation by creating a rigid connection between the child seat and the vehicle's actual structure. Before its introduction, the only method was the seatbelt, which was the source of numerous installation errors (twisted belt, insufficient tension, incorrect routing) that could drastically reduce the seat's effectiveness in the event of an accident. ISOFIX eliminates this uncertainty. Concretely, the system consists of two horizontal metal loops, welded to the car's chassis and hidden at the junction of the seat cushion and backrest of the rear seats. They are often indicated by a small ISOFIX tag or logo.

How does an ISOFIX installation work?

Installing an ISOFIX car seat is child's play. The seat is equipped with two retractable metal arms or latches. You simply align them with the vehicle's anchorage points and push them until you hear a distinct 'click'. This audible signal is almost always complemented by a visual indicator on the seat's connectors, changing from red (unlocked) to green (locked). This double confirmation offers unparalleled peace of mind for parents. Once both latches are locked, the seat is securely attached to the car, preventing any lateral movement and ensuring optimal restraint.

The third anchorage point: Top Tether or Support Leg

For perfect safety, the two-point ISOFIX system must imperatively be supplemented by an anti-rotation device. In the event of a frontal impact, the car seat tends to tilt forward. This third anchorage point prevents this dangerous movement. There are two solutions:

The Top Tether:

This is a strap located at the top, on the back of the car seat. It attaches to a specific anchorage point in the vehicle, generally located on the back of the seatback, on the rear parcel shelf, or in the boot floor. This point is identified by an anchor pictogram.

The support leg:

This is a telescopic leg extending from the base of the car seat and resting firmly against the vehicle floor. In addition to its anti-rotation role, it absorbs part of the impact energy by transferring it to the floor. Please note that its use is sometimes incompatible with vehicles equipped with under-floor storage compartments.

ISOFIX vs Seatbelt: What are the advantages?

Road safety studies are clear: ISOFIX is much safer. The main reason is the drastic reduction in the risk of installation error. It is estimated that more than 2 out of 3 seats secured with a seatbelt are incorrectly installed, compared to less than 5% for ISOFIX seats.

The advantages are numerous:

Direct connection:

The seat becomes one with the car, which improves restraint and reduces the forces exerted on the child.

Simplicity and speed:

Installation takes a few seconds and leaves no room for doubt.

Stability:

The seat does not move during cornering or braking, offering greater daily comfort and safety.

Universality:

The standard guarantees compatibility between vehicles and the car seats equipped with it.

In France and across Europe, the presence of ISOFIX anchorages (at least on the two outer rear seats) has been mandatory on all new vehicles since February 2011. The more recent i-Size (R129) regulation for car seats even mandates the use of ISOFIX for enhanced safety. Today, it is an essential selection criterion for anyone transporting children.