Is an isofix car seat install safer than a vehicle belt car seat install?

These days a lot of newer car-seats, especially European standard, come with isofix. But what is isofix and, more importantly, is it safer for your child?

What the heck is isofix?

Isofix is an international standardising fitting systems for car seats. The ISO part actually is an acronym for International Standardization Organisation. Fix is short for Fixation.

Isofix systems use specific points in the car to affix to the car-seat base. Usually there are two specific points in the seat which are the isofix points that the seat attaches to.

Can you double the safety, by using isofix and a seat belt to install?

If you install a car seat with an isofix, then you will not usually use the vehicle's seat belt for the install too. While it may be tempting to do both, it's usually recommended that you don't because the seats are not tested with both in use and the manufacturers cannot guarantee you won't compromise safety.

Some seats will offer the option between a seat belt install or an isofix (or latch) install. These can be useful because you get to choose and can opt for the install method that keeps your seat more stable. 

That said there is an exception to this general rule: booster seats. This uses isofix to stablise the seat itself, whilst the vehicle belt secures your child and their seat, for added security.

Is isofix safer than a seat belt?

The safety is the same if you have installed the seat in compliance with the car seat manual and with the car manual.

One benefit to the isofix, over the vehicle belt install, is that it's really easy to install the isofix tightly while sometimes it's hard to get a vehicle belt install tight enough. It is also harder for a child to undo the isofix. 

One benefit to a seatbelt install, is that a seatbelt does not have the same weight limitations as an isofix install. You will need to refer to your car seat manual and your car manual to determine the maximum weight for isofix.

To increase safety with either install, it's important to also use an anti-rotation tether or support leg if you have one on your car seat. This decreases the movement of your child in the event of a sudden stop or crash, and therefore minimises the risk of injury.

What would we recommend: isofix or seatbelt?

We don't have a straight up recommendation. This is context specific.

When installing a capsule for a newborn, if isofix is an option, I would often recommend that is used. Isofix is great if you find it difficult to install your car seat firmly into your vehicle using the vehicle belt.  It's also nice having a car seat that has i-size European safety features (which would include isofix and extended rear-facing). 

A seat belt install is often better for Japanese imports which don't necessarily have isofix, or for heavier children. Similarly, if you are likely to move the seat from car to car, and share pick ups with people in different vehicles that do not contain isofix, then your best bet may be to opt for a vehicle belt install.

Have you got questions about isofix?

I hope this brief article helps you understand isofix a bit better. If you have any general questions please pop them in the comments below as we're sure other parents will have similar ones.

Otherwise, if you have any questions about isofix, or whether isofix is installed in your car, please chat with us - we're always happy to help.