Which? believes the Smart Kid Belt, a device designed to remove the need for a high-back booster car seat, should be avoided because it's unsafe.
Although this car seat accessory meets the minimum legal standard, crash testing carried out by the Which? car seat lab has found that the accessory, which is designed to pull the vehicle seatbelt into an appropriate position across your child's chest and abdomen, does not provide adequate protection.
Find out more about the Smart Kid Belt, as well as why it's so important to use a high-back booster seat with your child until they reach twelve years old or 135cm in height.
The Smart Kid Belt is a belt guide consisting of two red clips attached to a length of belt.
The idea is that you clip it to the adult seatbelt to pull the diagonal and horizontal straps down and up.
It's designed to remove the need for a high-back or backless booster seat, as it supposedly makes the adult seatbelt sit across the correct parts of a child's body to provide protection in a crash.
The Smart Kid Belt is designed to be used with children aged four to 12 years and is available in the UK from Amazon and Ebay for around £20-30.
The Smart Kid Belt is currently approved to R44 regulations.
However, when our test house carried out its own crash tests on it, we discovered the product doesn't keep the shoulder part of the vehicle seatbelt low enough in a frontal collision.
The horizontal lap belt section also pulls up during a crash, meaning it could put pressure on your child's delicate abdomen area and potentially cause dangerous internal injuries.
In addition, the Smart Kid Belt will not provide the same level of side impact protection that a high-back booster seat does as there are no protective side-wings around the head and neck.
We believe that using the Smart Kid Belt would not be much safer than transporting your child using just the vehicle seatbelts; something that is prohibited for children who are less than 135cm in height.
For these reasons, we recommend that you do not buy the Smart Kid Belt, and if you have bought it, you should stop using it immediately.
The manufacturer of the Smart Kid Belt told us it thinks it's being unfairly targeted by market competitors.
The company says it's had the Smart Kid Belt independently tested to the relevant Standard, and the results prove that the Smart Kid Belt is safe and effective.
The picture below demonstrates how a high-back booster seat will protect your child.
The seat base of the high-back booster raises the seating position of your child, meaning the diagonal part of the vehicle seatbelt sits on the shoulder without being too close to the child's neck, where it may dig in during a crash.
It also means the horizontal part of the seatbelt sits across the very top of the child's legs where their hips are. This is one of the stronger areas of a child's body, and more likely to withstand the pressures of a frontal impact crash, as opposed to the soft abdomen area.
The side wings and head rest of the high-backed booster seat will protect the child's head and body.
Which? has been helping to keep children safer in cars for more than fifty years, and our car seat testing goes beyond the legal regulations for the UK and Europe.
We crash test each child car seat we review and carry out fitting and comfort checks using parents and their children.
Our crash tests are severe and our experts feel that they more accurately reflect what happens in real crashes than the legal minimum regulation that manufacturers are required to adhere to in order to sell their products.