What is ISOFIX?
ISOFIX is an international standard system that allows you to fit a car seat directly into a vehicle without using the seatbelt. It was designed in the 1990s to provide a quick, easy and safe way of installing a car seat but didn’t become widely used until 2006, when it became law for new cars to be manufactured with ISOFIX fittings.
How does ISOFIX work?
ISOFIX car seats have two arms on the back of the seat that hook, or anchor, onto to two small metal bars in your vehicle (you’ll find these at the point where the back seat meets the seat cushion). By pushing the seat backwards onto these anchor points, the seat locks directly onto the chassis of the vehicle.
Is there just one type of ISOFIX?
Confusingly, there are three ISOFIX systems in circulation. All of three systems use the hook and bar method of locking the seat in place but the most recent have additional fixing points on the floor of the car, or above or behind the seat. These additional fixings prevent forward rotation (without these, in a crash situation the car seat may sink into the seat cushion and lurch forward, which is potentially damaging to your child’s neck and spine).
Check your car’s manual to find out which of the three ISOFIX systems your car uses:
- Semi Universal - in addition to the hook and bar, a top tether or foot prop is used. Can be used with ISOFIX child seats that can face forwards, rearwards or side ways (i.e. lie-flat car seats)
- Universal - used only with forward facing, Group 1 seats. Uses a top tether, in addition to the hook and bar, to fix the seat to an additional anchorage point.
- Vehicle Specific - uses only the anchor point to secure the seat. This method is vehicle specific and is only compatible with certain vehicles. The make/model of suitable cars is usually named on the box of the car seat or on the manufacturer’s website.
There are also several different size classes of ISOFIX seat that take into account the different sizes of car - a full height forward facing car seat might not fit into the back of a Mini, so you’d need to shop for a reduced height seat.
The positive points of ISOFIX
ISOFIX scores highly in the safety stakes. By plugging your car seat onto your vehicle you’re reducing the chance of fitting it incorrectly.
A study of Group 1 seats, conducted by the German Insurance Institute (GDV), found that 96% of seats fitted using ISOFIX were installed properly. In comparison, the same study found that only 30% of car seats were fitted correctly when the adult seat belt was used. This is because the seat belt anchor points vary in size, length and position from car to car, so creating a seat that fits perfectly in every car is virtually impossible.
ISOFIX is also a quick and simple way of getting the car seat in and out and makes light work of using a travel system.
The downsides of ISOFIX
By law, all new cars must be fitted with ISOFIX points but not all ISOFIX car seats will fit in every car, so do your research before buying. This poses problems for two-car families who swap car seats between cars.
And ISOFIX car seats don’t come cheap - you may end up paying double the price of a non-ISOFIX model.
If you’re about to buy a car seat for you baby, toddler or child, our buyer’s guide to car seats will take you step by step through finding the right one.
