Choosing a baby or child car seat

The safest way for babies and children to travel in a vehicle is to select a car seat which is suitable for their weight and size and has been correctly fitted. Using a rear-facing car seat for as long as possible, until they reach the highest weight or height allowed by their car safety seat manufacturer, is the safest way to travel.

If a vehicle crashes, a properly-fitted child car seat will help to prevent the child from being thrown about inside the vehicle or being thrown out of the vehicle. Car seats absorb some of the impact force and provide some protection from objects coming into the passenger compartment.

The law requires all babies and children travelling in a vehicle to use the correct child car seat until they are either 135 cm in height or 12 years old (which ever they reach first). After this they must use an adult seat belt. There are very few exceptions. Read more about child car seats and the law.

To find out more, including links to additional guidance and advice, read our frequently asked questions below.

How can I find out about baby and child car seat safety?

The RoSPA child car seat safety website offers lots of advice about choosing a car seat as well as travelling safely with children.

You can also find advice from any good car seat retailer or manufacturer. We recommend that you ask to speak to a member of staff with experience in fitting seats. This will preferably be someone who has Institution of Occupational Safety and Health (IOSH) Child Seat Safety Awareness training, or who has been trained by seat manufacturers. You can check who is qualified in your area at Child Seat Safety.

What key things should I think about when buying a baby or child car seat?

There are many different types of car seats on the market, so take your time when choosing. Make sure you get the most suitable seat for your child and your car.

Try to take your child and your car with you when choosing your child car seat and find an IOSH trained retailer whose staff are trained in selecting and fitting child car seats. Find a retailer who will help you try the seat in your car before you buy it.

In summary, your choice of child car seat must:

  • Conform to the United Nations standard, ECE Regulation 44.04 (or R 44.03) or to the new i-size regulation, R129. Look for the ‘E’ mark label on the seat. Io
  • Be suitable for your child’s weight and size
  • Be correctly fitted according to the manufacturer’s instructions

Visit RoSPA Child Seat Safety to find out more about choosing, buying, fitting and using a car seat.

The NHS also has information about choosing a baby seat

Who in Portsmouth can check that my child car seat is properly fitted?

In Portsmouth, the car seat retailer, Baby 2000, in Copnor Road offer safety checks and guidance from IOSH trained members of the team but you can get advice from any IOSH trained car seat fitter.

Will a car seat fit to all types of vehicle?

Not all seats fit all cars. When buying a new car seat, arrange for a trained member of staff to complete a fitting trial for you in all the vehicles the seat will be used in or speak to your car manufacturer.

Take precautions when buying online and make sure that the car seat you buy meets the safety requirements recommended by RoSPA

How do I check a car seat is safe to use once installed?

Check the following to make sure your baby or child seat is safe to use:

  • Headrest height

The child’s eyes should be in line with the thickest part of the headrest.

  • Harness height

For a rear-facing car seat the harness should be just on or slightly below the child’s shoulder height. For a forward-facing seat the harness should be just on or slightly above the child’s shoulder height.

  • Damage from being left in a car

Make sure that there is no visible damage to the seat by lifting the covers and checking the polystyrene underneath.

  • Seatbelt tension

Over time seatbelts can loosen, so make sure the car seat is correctly fitted with the right tension.

  • Battery life

If your car seat or Isofix base requires batteries, make sure they’re working correctly.

Always check the manufacturer instructions and seek advice from a good car seat retailer if you are unsure. We also have a useful car safety check video with useful advice about safely fitting a child car seat to your vehicle.

Who can I contact if I have more questions?

You can contact a friendly member of the road safety team who can help give you advice and guidance. Call 023 9268 8262 or email us


While we recommend Baby 2000 and other retailers who are IOSH trained, ultimately it is parent or carer’s responsibility to ensure that the child seat fitted in their vehicle is fit for purpose.