What is ISOFIX?

ISOFIX is the international standard for attachment points for child safety seats in passenger cars. The system has various other regional names including LATCH ("Lower Anchors and Tethers for Children") in the United States LUAS ("Lower Universal Anchorage System") or Canfix in Canada. It has also been called the "Universal Child Safety Seat System" or UCSSS.

ISOFIX is International Organistation for Standardisation standard ISO 13216, which specifies the anchoring system for Group 1 child safety seats. It defines standard attachment points to be manufactured into cars, enabling compliant child safety seats to be quickly and safely secured. ISOFIX is an alternative to securing the seat with seat belts. Seats are secured with a single attachment at the top (top tether) and two attachments at the base of each side of the seat. Top tether points became mandatory in all new vehicle models in 2013.

In the EU the system known as ISOFIX, was introduced in 1997. It covers both Group 0/0+ and Group 1 child safety seats. In the EU two "alligator-like" clips connect the seat to the lower attachment points. In the European standard, there are also various installation categories, detailed below. For Group 2/3 seats there is a system called ISOFIT which anchors the seat to the vehicle so it cannot slide around when not in use. In the case of ISOFIT, the child is held into the seat using the vehicle's existing seat belt system, not the safety seat straps.

There are 5 types of car seat approvals: Universal, Semi-Universal, Restricted, Vehicle Specific and Special Needs. This allows you to know if a seat fits your car and is approved to the safety standards for it. Universal approval isn't vehicle specific, and the seat is approved for installation in all cars. You should however check that the seat fits really well in your vehicle.

Universal approval

‘Approved’ for use in vehicle seating position assessed as compatible with child seats under UN Regulation 16. These seats will typically use a ‘top tether’

Semi-universal approval

‘Approved’ for use in vehicles that are referenced in a child restraint fitting list. This is sometimes known as the ‘application’ list showing which car the seat is suitable for.

Restricted approval

‘Approved’ for use in a designated seat position for a particular vehicle type, as indicated by the child restraint manufacturer or the vehicle manufacturer.

Vehicle specific approval

‘Approved’ for use in specific vehicles or child restraint systems ‘built in’ to the vehicle. This means seats that have been test when the whole vehicle underwent testing.

Special Needs approval

‘Approved’ for children who have special or additional needs. It is a child restraint that complies with R44, but can have additional restraining devices to suit the need.

What is the "current list of approved cars" in connection with ISOFIX?

Child seats are approved to ECE R 44/03 and 44/04 in various categories, always for different modes of installation and use. In some cases, especially for the installation with ISOFIX, the cars in which the seats are approved are shown in a "current list of approved cars". For some seats, several installation modes are applicable.

It is also necessary when fitting any child car seat, to review the child car seat section of your vehicle manual, to make sure that there is a general 'approval' for child seats.