Car seat safety

In the UK, children must use a suitable child restraint until they reach 12 years of age or 135 cm (4 ft 5 in) in height, whichever comes first. After this point, they must use the vehicle's adult seat belt. Although the legal requirement ends at 135 cm or age 12, road safety organisations recommend that children continue using a suitable booster seat until they are around 150 cm tall. Adult seat belts are designed for adults and may not fit a smaller child correctly across the shoulder and pelvis. 

There are two types of approved child seats currently used in the UK: 

• R129 seats are selected primarily according to the child’s height, with a maximum weight specified by the manufacturer. They include side-impact testing. 
• R44 seats are selected according to the child’s weight and are divided into Groups 0, 0+, 1, 2 and 3. R44 is the older approval standard, but appropriately approved R44 seats remain legal to use in the UK. 

Parents and carers should always read the instruction manual supplied with the child seat and follow the vehicle manufacturer's guidance on child restraint installation. Many child seat manufacturers also provide step-by-step installation videos on their websites or YouTube channels, which can be a useful guide when fitting the seat for the first time. 

Before every journey, check that: 

• The child seat is securely fitted, does not move excessively at the ISOFIX bar points or seatbelt path, and the seatbelt is not twisted; 
• The harness is correctly adjusted and fits the child snugly, with no twists in the straps; 
• Any inserts are fitted or removed in accordance with the manufacturer's instructions; and 
• Support legs, rebound bars or top tethers (where fitted) are correctly positioned. 

If you are unsure whether your child seat has been installed correctly, contact the retailer or manufacturer for advice. 

ISOFIX connectors attach the seat to the vehicle, but they are only one part of the installation. Most ISOFIX child seats also require a support leg or top tether, which must always be used in accordance with the manufacturer's instructions. 

If you do not know whether a seat has been involved in a collision, has been damaged or stored incorrectly, it is difficult to be certain that it will continue to protect a child as intended. 

Second-hand seats are also sometimes sold without instructions or essential parts, increasing the risk of incorrect installation. Before using any second-hand seat, check that it is complete, in good condition, still supported by the manufacturer, and that your car insurance policy allows its use.

Even if there is no visible damage, a child seat may have sustained internal damage that could reduce its effectiveness in a future crash. If there is any doubt about whether a seat remains safe to use, contact the manufacturer for advice or follow the official manual for guidance. 

Many motor insurance policies also cover the cost of replacing a child seat following a collision, so it is worth checking with your insurer.

Manufacturers specify how long their child seats are designed to be used, and this varies between brands and models. 

Parents and carers should check the manufacturer's guidance or the label on the seat to determine its recommended service life. 

Newborn and infant inserts help position smaller babies correctly within the seat. They may support the baby’s head and body, improve the fit of the harness and help maintain the position intended by the manufacturer. 

The inserts should not be removed simply because the seat appears tight or the baby looks uncomfortable. Child seats are tested and approved using the components and configurations set out in the manufacturer’s instructions. Removing an insert too early may alter the child’s position, create space around the body or affect how the harness fits and performs in a collision. 

Different inserts may have different removal points. Some are removed according to the child’s height or weight, while others are intended to remain in place for longer. Parents and carers should check the instructions for their specific seat and remove each insert only when directed by the manufacturer.

Rear-facing seats provide better protection for a child’s head, neck and spine by spreading collision forces across the back of the seat. Under the R129 child seat regulations, children must remain rear-facing until they are at least 15 months old. This is the minimum legal requirement for R129-approved seats. Some child seats approved to the R44 standard can legally be used forward-facing from 9 kg. However, it is strongly advised not to turn children forward-facing as soon as they reach this minimum weight. 

Parents and carers should continue to use a rear-facing seat until their child reaches the maximum height or weight permitted by the seat manufacturer. For many seats, this is four years old. They should not move to a forward-facing seat simply because their child's legs appear bent or their feet touch the vehicle seat.

Although children can legally travel in the front passenger seat, the rear seats are generally considered the safest place for child passengers. If a child seat is to be fitted in the front passenger seat, the instruction manual should be consulted because not all manufacturers design seats to be used in that location.  

A rear-facing child seat must never be used where there is an active passenger airbag. If a rear-facing seat is fitted in the front passenger seat, the airbag must be deactivated first. If the airbag cannot be deactivated, the child seat must be fitted in a suitable rear seat instead.

Only accessories supplied or approved by the child seat manufacturer should be used. 

Child seat manufacturers test approved accessories alongside their products to ensure they do not affect how the seat performs in a collision. Using unapproved accessories could affect the way the seat works and may invalidate the manufacturer's warranty. 

Parents and carers should always follow the manufacturer's guidance before adding any accessory to a child seat.

All child seats sold for use in the UK must meet minimum legal safety standards – R.44(.03), R.44(.04) or R129. 

However, child seats differ in their design, ease of installation, comfort and features. When choosing a child seat, parents and carers should consider how well it fits both their child and their vehicle, how easy it is to install correctly and whether it has performed well in independent safety tests. Price alone is not a reliable indicator of safety. 

UK law provides limited exemptions for children travelling in licensed taxis and private hire vehicles when a suitable child restraint is not available. However, these exemptions should only be relied upon when there is no practical alternative. 

Where possible, children should always travel in a suitable child restraint appropriate for their age, height and weight. 

When travelling by coach, parents and carers should check the operator's seating and seat belt arrangements before travelling. Where appropriate and permitted, a suitable portable booster may help position the seat belt more safely for older children.