What's the best Car Seat fitting

Car seats for infants can be attached using Isofix fittings or seat belts. But how do you decide which is the best option? We’ve set out the pros and cons below to help you make up your mind.

Whichever method you choose, remember that it’s absolutely crucial to instal your car seat correctly. The seat must be firmly fixed to the car to help restrain your child and minimise the chance of life-threatening

Advantages of ISOFIX

Ultimately, we advise you to use ISOFIX rather than car seat belts to install your car seat. ISOFIX:

  • minimises the risk of incorrect installation. Child car seats fitted using seat belts are often installed and used incorrectly.
  • provides a solid, permanent connection between the car seat and the car body.
  • is proven to be outstandingly safe in tests. 

Knowing this, let’s go through the pros and cons of both types of installation:

Seat belt method


  • It’s safe if installed properly
  • It’s flexible – not all cars have Isofix so it’s easy to switch your car seat between cars.


  • Up to eight in ten inexperienced parents instal their car seat incorrectly when using a seat belt. This dramatically reduces the protection offered to your child in a crash. Car seats that use seat belts take more time to install than those installed with ISOFIX.
  • The most common mistakes are not pulling the belt tight enough, or leaving the belt twisted. It’s also easy to make a mistake if the car seat has no obvious way to fit the belt through it.


Isofix method

Most cars manufactured over the past ten years have Isofix fittings. This means that you can quickly click an Isofix car seat securely into place without the need to use a seat belt.


  • Safety tests show that it’s extremely safe, providing a strong and rigid connection to the car frame.
  • The risk of incorrect installation is low – 94 per cent of parents use Isofix correctly.
  • It’s fast and easy: just one click attaches the car seat solidly to the car.
  • An extra support leg or top tether strap increases stability and minimizes forward movement, keeping your child securely in place.
  • Booster seats can be permanently secured using Isofix.


  • Not all cars have Isofix. Check the car fitting list to see if yours has.
  • Some Isofix seats cannot be installed using a seat belt, offering less flexibility.
  • Isofix seats are often more expensive than belt-based seats due to the construction and reinforced materials needed to make it super safe.
  • An Isofix seat generally weighs more than a belt-based seat, although this isn’t always the case.


More car seat safety tips

Go to Isofix car seats and get an answer on what is Isofix?