Common car seat fitting errors and the risks

The peril of incorrect fitment and why you should get your car seat checked

An incorrectly fitted child car seat will not work to the best of its ability in a collision, if at all.  Here are some of the more common car seat fitting errors we come across, and the potential risk associated:

Loose harness

A child car seat harness is there to keep your child in their car seat in the event of a collision. It also helps to spread the force of the crash, further protecting your child.  A loose harness will not be able to restrain your child properly, and they are at risk of travelling too far forward in a collision.  This could cause them to impact the interior of the vehicle, or come out of the harness altogether if it is very loose.

To fix: Remove all puffy and thick clothing from your child, and pull the harness tight enough to allow you to slip two fingers flat between your child’s chest and the harness, at collar bone level.

Incorrect harness height

Child car seat harnesses must be adjusted as your child grows to restrain them properly, and we often find harnesses on group 1 car seats to be too low on children.  On forward facing children, this is particularly a problem as it can cause the harness to sit incorrectly on the child, causing a risk of the harness slipping off their shoulders and not restraining them.  It may encourage them to remove the harness due to discomfort, which is extremely dangerous in a collision.

To fix: The correct harness height is for the straps to be level with a child’s shoulders, at the point they come out of the child seat.  If you cannot get them at the same level as their shoulders, then they may dip below when rear facing, or sit just above the shoulders when front facing.

Slack seat belt

On child car seats fitted with the adult belt, it is important that there is no slack on the belt, and that the belt is straight and untwisted.  A slack seat belt will cause the child seat to travel too far forward in a collision, potentially hitting the seat in front or the interior of the vehicle.

To fix: When fitting your seat, push your knee firmly into the seat, whilst you are doing this, pull the adult belt tight and lock off with the appropriate guides.

Incorrect seat belt routing

We often have to demonstrate the correct routing of the adult belt as many people become confused with the fitting instructions.  An incorrect belt route carries a risk of the seat moving too much in a collision, to it not being restrained at all and exiting the vehicle altogether.

To fix: Read your manual carefully, watch manufacturer fitting videos, seek professional help and get your child seat checked.

High back booster adjustment

The headrest on high back boosters are often not increased with the child as they grow, which causes the adult belt not to sit across their shoulder safely.  In a collision the chest part of the belt will not be able to restrain their upper body correctly.

We also see younger children being allowed to use older siblings' seats as a ‘treat’ – to use another group stage seat a child must first be a suitable weight and height for the seat.  If the child is not big enough for the seat, they should not use it, and if they fit into their own seat, they are safest using that.  If they are the correct weight and height, then the booster head rest should be adjusted to suit the child’s height.

To fix: Most high back boosters have a squeeze handle at the top of the head rest.  Squeezing this handle will allow you to increase the height of the headrest to suit your child.

Watch our video on common car seat fitting errors.