Car seats for older kids

[shishnfips]

Sorry not necessarily an aibu but not sure where else to put this. Dd1 is 8y9m, 91st centile for height but skinny, doesn't weigh a lot at all. She's in a highback booster still much to her annoyance as she says all her other friends don't have anything. I thought you had to be 12? Or are there other conditions? Obviously my priority is safety here.

Children must normally use a child car seat until they’re 12 years old or 135 centimetres tall, whichever comes first.

It's 12 years olds or 135cm tall whichever comes first.

According to the RAC site here www.rac.co.uk/drive/advice/road-safety/car-seat-laws/

“Children of 12 years old or taller than 135cm do not need to use a child seat”
And
“backless booster seats are only approved for children weighing more than 22kg or taller than 125cm.”

My eldest moved onto a booster at 9 purely because of height. He is now 10 and found the booster was uncomfortable so doesn't use a car seat anymore. I thought he would be a high back booster til 12!

My 9 yo is just on a booster cushion now as the proper booster seat was too short for him.

My 7 year old will soon be over 135cm. I plan on keeping her in seat as long as possible. The back think is adjustable so I hope it will last for another few years (and as close to 150cm as I can get)

From high back booster she will go seatbelt.
Shenwil

Ah well I've just measured her and she's approx 137cm. So...no need for a highback

Thanks all!

We use high back for long journeys on fast roads for ours 9&7. Depending on the number and heights of the kids we regularly transport, we use a combination of high backs, boosters and nothing going for the safest and best fit. The tall 9yo still uses a booster in the front just because of the height of the seatbelt attachment. Probably I should use one too at 44...

Whilst they are not legally required once over 135cm, there are other markers to suggest if the kids are big enough. See here for example.
My 9 year old is over 135, but doesn't meet all of these. I'm aiming to keep him in a car seat until as close to 150cm (Regulations in most if Europe) as I can.