What is Isofix?

This article explains Isofix and why it’s a great feature in a car seat

At phil&teds we’re parents too so we understand what parents need to get through the parenting day. A car seat is the first purchase most parents make. We want to decode this confusing decision by explaining what Isofix is and why it is a great invention.

isofix alpha with philandteds mod @ale_samaniego

mod & alpha travel system – Photo credit: @ale_samaniego

Let’s start with a definition:

Isofix is an internationally recognised car seat restraint securing system. It’s a secure point in the back seat of a car that you can attach car seats to. The secure point is a ‘lug’ that sits between the bottom and the backrest of the seat. Isofix lugs are easy to find. Simply run your hand between the seat and backrest behind the passenger and driver’s seats and you will find them. They are metal and very solid. In some cars the location is marked and is very obvious.

isofix lugs

What does Isofix mean?

Although it sounds like it, Isofix is not an acronym. It’s a universally accepted turn of phrase that is understood wherever you are in the world. It is recognised by the International Organisation for Standardisation (or ISO) and is a safety feature being rolled out on most new build cars today.

What makes Isofix so great?

Isofix is an exceptionally easy way to secure a car seat into the car. The car seats attach to Isofix lugs with clamps. The clamps have ‘teeth’ that safely secure the seat onto the lugs. A seat is secure if you hear an audible click from the arms when marrying to the lugs. Once the seat has been clipped into the lugs you then need to make adjustments in order for it to be safe for children. The two adjustments that need to be made are:

  • Push the seat / base as close to the back of the seat as possible
  • Adjust the height of the seat to ensure it’s level – see car seat instructions for more details

Isofix lugs are not found in all cars. The first Isofix products appeared in 1997 and fit new model Volkswagen vehicles. Since then it has grown to become an important safety feature in most new cars. As of 2014, all European cars are required to have Isofix connectors.

extended isofix lugs


Most countries have taken steps to make Isofix lugs a mandatory feature in cars. Though, some regions use slightly different connectors that are not called Isofix. An example is the USA. They use the ‘Latch’ system. Latch is an acronym for ‘Lower Anchor and Tether for Children’. A latch connector is made specifically for an Isofix lug but is different to the connector.

Seat belt installation in vehicles

Under the European R44/04 standard, car seats need to be restraint with a seat belt at the bare minimum. It is essential that the correct process is used to thread the seat belt harness safely. A seat belt restraint system is more complicated than using Isofix lugs. Once installed in your car with a seat belt, have the car seat checked by a trained car seat professional. They will ensure that it has been safely installed. The best bet for checking a car seat is to use a trained Car Seat Restraint Technician.

A Car Seat Restraint Technician is a qualified person who specializes in car seat restraints. They are experts in car seat installation and can advise you on what products will be best for your child. Every family has different needs and not every car seat will fit into every car. If you are overwhelmed with the choice of car seat restraints available, or have any question about the installation of your seat, speak with your local car seat restraint technician.

Fun fact: in the USA, seat belts weren’t a standard feature in cars until they were legislated on the 1st of January, 1968!

Our alpha car seat has an Isofix base

Available in Europe and New Zealand, the alpha Isofix base is very easy to use. The Isofix base is also easy to install. See this video for a demonstration of the Isofix base:

The great thing about the Isofix base is that it makes it easy to move alpha in and out of a car. As a parent you’ll need to install and remove the car seat at least twice on every single outing. That’s if you only stop once. Every time you park the vehicle you will need to do the same thing, which could amount to several different times per trip. If you have a car seat base, you can unclip it as easily as you clip it in. Without a car seat base you have to install the car seat with the seat belt every single time.

Seat belt installation is great, but not the most convenient option if your child is resting in the seat. Why? Because it can be challenging to thread and re-thread the seat belt every time you install without disturbing the baby.

The benefits of an Isofix base with alpha are:

  1. Convenience
  2. Ease of use
  3. Guaranteed safe install, every time!

alpha also fits on all phil&teds buggies as a travel system.

Good luck with your car seat purchase. We hope this article has made your decision slightly easier. If you would like to learn more about alpha, visit phil&teds.com.

Visit phil&teds.com>



About the author:

Let's adapt&survive the parenting day together! Visit our tips&tricks section to find more interesting parenting trivia. Remember to leave a comment and share this with your friends..

One comment on “What is Isofix?

  1. Pingback: What is LATCH? -