The law says that all children travelling in a car or van who are under the age of three must travel in an appropriate child restraint.
Furthermore, youngsters over three years old - and 135cm tall or less - must also use an approved safety seat. Note: 12 year olds who are less than 135cm tall do not have to use an approved safety seat, but, of course, still have to use a seat belt.
The only child and baby seat exceptions are:
* a short journey in an emergency
* a taxi journey when a restraint is not available
* if two child restraints in the back means a third can't be fitted
* trips in older vehicles with no rear seat belts - in such this case, children 3 years and over may travel unrestrained
The driver is responsible for ensuring all child occupants are safely seated up to the age of 14. In addition to legal penalties (a fine of up to £500), failure to do so could also affect any claims against their car insurance cover.
Car seat compliance
All child restraints must comply with United Nations Economic Commission for Europe (UNECE) regulation 44.03. Since 2008, the number of passengers in a car must not exceed the number of seat belts - whether in a child seat or not.
Which type of car seat should I buy?
There are five groups of child restraint, determined by the weight of the child:
* Group 0: up to 10kg (birth to 9 months)
* Group 0+: up to 13kg (birth to 12 months)
* Group 1: 9-18kg (9 months to 4 years)
* Group 2: 15kg upwards (4 years+)
* Group 3: 22kg upwards (6 years+)
The ages are approximate. A more reliable indicator of which seat to use is the weight.
Group 0 and 0+ tend to be rear-facing seats, which are much safer when babies are very small. Group 1 and upwards tend to be forward-facing seats.
Is my child's car seat compatible with my car?
Most cars will accept car seats attached with a seat belt alone. Modern cars offer the ISOFIX system - this provides mounting points on the seat for a more secure fitment. It's crucial to ensure the seat is compatible with your car.
Where should I put my child's car seat?
The back seat is the safest place in the car for your child. For extra protection, put them in the nearside seat - that is, the side closest to the pavement. Your child will be further away from oncoming traffic, plus it's easier for a driver to keep an eye on them.
Top tip: If you're on your own, you may want to put a baby in the front. Ensure any passenger airbag is switched off and the seat is pushed back as far as it will go. DO NOT place a baby in the front passenger seat if there is a passenger airbag.
3 tips for fitting your child's car seat
Nice and tight
If you're fitting a car seat using the seat belt, use your knee and bodyweight to force the seat firmly into position. Tighten the belt, ensuring it feeds through without any twists.
It should be tight enough that the seat won't rock in any direction if you pull it.
Adjust the angle of the car's seat so the child is slightly reclined - this will avoid their head lolling forward when they fall asleep.
Belt up
With the car seat in, make sure the straps fit properly. Loosen them before putting the child in. The belts themselves should be tight enough to hold the child in place, but not uncomfortably so. Tighten straps so that you are just able to slide two fingers under the belts.
Daily checks
Check the seat has not become loose - undo the belt and re-attach if necessary. Check the adjustment of the child's straps every time they get in the car.