Common Errors

Sadly around 70% of all car seats in the UK are being used incorrectly. This page shows some of the most common errors that are putting children's lives at risk


Forward facing too early

Children's skeletons, and in particular the neck and spine, are not mature enough to cope with the forces of a crash until they are at least four years old. Therefore forward facing is not a milestone you should look forward to or rush into. Forward facing R44/04 car seats can legally be used once a baby weighs 9kg, but for some babies that is as young as five or six months! And even R129's 15 month minimum doesn't go far enough. It is much safer to move your baby into an extended rear facing seat when they have outgrown their infant carrier, and to keep them rear facing until they are at least four years old and no longer fit in the seat. Some of the larger rear facing seats will last for six or even seven years.

This seat is installed correctly, but at 21 months old this little boy is much too young to face forward. In a seat like this he is five times more likely to be seriously injured in a crash, than in a rear facing seat.

The Harness

A harness that is loose or twisted won't protect your child in a crash. You shouldn't be able to fit more than two fingers between the straps and the child's chest. The straps should fit snug on the child's shoulders, not hang off the top of their arms. All parts of the harness straps should lie flat on the child's body. If the straps are twisted they can't distribute the crash forces evenly.

In this photograph he is in the right seat for his age and weight, but the harness is much too loose. One side is twisted and the other side is falling off his shoulder. A harness used in this way will offer the child little or no protection in a collision.

Here the harness is positioned on the shoulders, it is not twisted and it is adjusted tight enough so that no more than two fingers can fit between the strap and his shoulder. Used in this way the harness does two jobs, it keeps the child in the seat and it distributes the crash forces evenly across the body.

Seat Belt Routing

All car seats have guides that show where the seat belt should be routed to hold the seat firmly in place in your car. In R44/04 seats these are blue for rear facing and red for forward facing, and in R129 seats they are all green. Most forward facing and extended rear facing seats also have a clip that the seat belt should be locked into. These clips are known as a lock-offs and are also blue for rear facing and red for forward facing in R44 seats, or green for both in R129 ones. If the seat belt is not routed correctly or not locked, the seat won't be safe.

besafe izo go incorrent belt routing
In this photograph the seat belt has been routed incorrectly and the carry handle is down. In a crash a seat that is installed in this way will not be retained by the seat belt.

besafe izi go
A correctly installed infant carrier. The lap belt goes over the baby's legs and the shoulder belt goes around the seat through the guide on the back. The carry handle is in the upright position.

Buckle Crunch

When a car seat is installed with the seat belt, it should be the seat belt webbing that holds the seat in place. In some cars the buckle stalks are quite long and this can result in the buckle resting on the plastic or metal structure of the car seat. This is known as buckle crunch and can cause the buckle to shatter in a crash. If you try a seat in your car and the buckle is too high, you can try a different position in the car, or you may need to choose a different car seat altogether.

joie steadi buckle crunch
This seat has been installed in a car with long buckle stalks. The buckle is too high and bends over the plastic structure of the seat.

This is how the seat belt and the buckle should look. The webbing is tight across the car seat and the buckle is flat.

Not Following The Instructions

It is very important to read the manual and follow it to the letter. Do not use the seat in any way other than those outlined in the instructions. You sometimes see people use infant carriers forward facing. Or harnessed seats used as boosters. Or children in boosters with the diagonal seat belt under their arm. Or with the lap belt routed across their stomach instead of their hips. The list is endless. Doing this or anything else that is not in the instructions is extremely dangerous. Using a car seat incorrectly is just as dangerous as not using one at all.

There are three things wrong here. The head rest is too high, the shoulder belt is under the child's arm, and the lap belt is too high because it has been placed over the booster's horns. Using a booster seat in this way puts the child at serious risk of suffering internal, spinal and head injuries.

This is how it should look with the headrest just above the shoulders, the lap belt under the horns and the diagonal belt over the shoulder.


Rear facing car seats are legal and safe to use on the front passenger seat, but only if there is no active frontal airbag. Airbags shoot out of their housing at 200mph and the force of the impact on the back of the child's seat is enough to seriously injure or even kill them.
So if you would like your little one to sit next to you, you have to switch the airbag off. This is possible in a lot of cars, but not in all of them. It is usually done with the key, the switch is either located in the passenger doorframe or inside the glove compartment. In some newer cars you can switch the airbag off in the control panel.

The advice on using forward facing car seats and boosters in the front seat varies from car to car, so you will need to consult the car's manual to see if the airbag should be switched off or stay on.

Using Booster Seats Too Early

High back boosters and even booster cushions without a back rest can legally be used from 100cm or 15kg, which is around three years old. But a three year-old's pelvis is not mature enough to cope with the force of the adult lap belt in a crash, and at three years old a child is usually not sensible enough to sit still in a booster. They need to be able to sit up properly in the seat and stay there for the entire journey. Children's skeletons are not mature enough to sit in a booster until they are about four and a half, so keeping them in their five-point harness until they have reached the weight limit is much safer.

britax kid fix
This may look ok, but it is very dangerous. The boy in this picture is only two years old and weighs 14kg. He is too young and too small to face forward, and too young to use an adult seat belt. A two year-old's skeleton is not mature enough to cope with the forces of a crash, and the seat belt can cause them serious injuries. And at this age they can't be trusted to sit still for the entire journey.

'We Never Used Car Seats And We're Alright.'

This is an argument that some people use to justify not using a car seat for their child, and it obviously makes no sense at all. The only reason that nothing happened to them is that they were lucky enough not to be involved in an accident, this is known as survivor bias. But every year nearly 300 children and their parents are not so lucky. That is how many children are seriously injured and killed on our roads every year. Everybody thinks it won't happen to them. But it does happen, and when it does it's devastating and can change your life forever. And that is why every child who travels in a car, no matter how short the journey, needs to be in a correctly used car seat to give them the best protection possible should the worst happen. Because you never know when that might be...