Car seats for babies: the rules and how to travel safely

The NHS recommends buying a baby car seat before your baby is born if you can. Here’s what the law, the NHS, RoSPA and The Lullaby Trust say about choosing one and using it safely.

The law

Gov.uk says children must normally use a child car seat until they’re 12 years old or 135cm tall, whichever comes first. Only approved child car seats can be used in the UK. Look for a label with a capital E in a circle.

Rear-facing seats

The Lullaby Trust says to choose a rear-facing baby seat, as this is essential for safety. The NHS says to use a rear-facing car seat for as long as your child fits into it, because these offer better protection in a crash. RoSPA says it’s best to keep your baby rear-facing for as long as possible.

i-Size (height-based) or weight-based seats

Gov.uk says you can choose a child car seat based on your child’s height or weight.

Height-based seats meet the i-Size regulation, R129. They have a label with a capital E in a circle and “R129”. Gov.uk says they must be rear-facing until your child is over 15 months old, and you must check the seat is suitable for your child’s height. The NHS says i-Size seats usually fit into Isofix points in your car, but some can be fitted with a seatbelt.
Weight-based seats have a label with a capital E in a circle and “ECE R44”. The seat your baby can use depends on their weight. For babies, gov.uk lists group 0 (0kg to 10kg) and group 0+ (0kg to 13kg). These are lie-flat or rear-facing baby carriers, or rear-facing baby seats with a harness. Group 1 seats (9kg to 18kg) can be rear- or forward-facing.

Fitting the seat

RoSPA says not all seats fit all cars, so check your car and the car maker’s instructions. If you can, visit a shop with trained car seat fitters and ask them to fit the seat in your car before you buy it.
The NHS suggests asking whether shop staff have been trained in fitting car seats.
Make sure the seat is fitted properly, following the manufacturer’s instructions.
Check whether your car has Isofix connectors. The NHS says these are designed to make fitting baby and child car seats simpler.
If your baby is likely to travel in another car regularly, check the seat fits that car too.
Gov.uk says you must only use a child car seat if your car’s seat belt has a diagonal strap, unless the seat is designed for a lap seat belt or fitted using Isofix. You must not fit a child car seat in a side-facing seat.
The NHS says to always put your baby into their car seat from the pavement side of the car.

The NHS says the road safety officer at your local council can give you detailed advice about child car seats. Look out for safety days where experts show how to fit seats safely.

Airbags

Never put a rear-facing baby seat in a front seat with an active airbag. The NHS says this is dangerous and illegal. Gov.uk says you must deactivate any front airbags before fitting a rear-facing baby seat in a front seat. The NHS adds that a forward-facing seat in the front, while not illegal, is not ideal.

Second-hand car seats

The NHS says not to buy a second-hand car seat. It could have been damaged in an accident, and it may not have all its parts, including the instructions. RoSPA says the damage may not be visible.

The NHS says only accept a car seat from friends or family if you know its history, it’s not too old, and it comes with instructions. RoSPA also says to:

check it carefully for damage
check the manufacturer’s age limit for replacing it
make sure it suits your baby’s weight and height
check it fits securely in your car

When you arrive

Take your baby out of the car seat as soon as you get to where you’re going. The Lullaby Trust says car seats aren’t designed to be a main sleeping place. If your baby is asleep, place them on a firm, flat surface to sleep. Use car seats for travel only, not instead of a cot or highchair. See newborn sleep and safe sleep.

Long journeys

The Lullaby Trust says young babies may be at risk of breathing difficulties if they sleep upright in a seated position for too long. It advises:

avoiding driving long distances with babies born early (pre-term) and young babies
stopping for regular breaks if you’re driving a long way
having a second adult in the back seat with your baby if possible, or using a mirror to keep an eye on them if you’re on your own
stopping straight away if your baby changes position and slumps forward
taking off hats and outdoor clothing, like snowsuits and coats, once your baby is in the car

Questions people ask

When can my baby face forward?

Gov.uk says height-based (i-Size) seats must be rear-facing until your child is over 15 months old. The NHS says to use a rear-facing seat for as long as your child fits into it.

Can my baby sit in the front?

Only with the front airbag deactivated. Gov.uk says you must deactivate any front airbags before fitting a rear-facing baby seat in a front seat.

Can I use a car seat from a friend?

The NHS says only if you know its history, it’s not too old and it comes with instructions. Don’t buy a second-hand seat.

My baby fell asleep in the car. Can I leave them in the seat?

No. The Lullaby Trust says to take your baby out as soon as you arrive and place them on a firm, flat surface to sleep.

Should my baby wear a coat in the car seat?

The Lullaby Trust says to take off hats and outdoor clothing, like snowsuits and coats, once your baby is in the car.