To still use a car seat for my 10 year old?

Used high back boosters until high school.

Our son is 9 and ~140cm.
He is still in his high-backed booster seat.
We deliberately bought one that expands width-ways as well as up as he grows, so he can stay in it as long as possible.

Not necessarily - they do top out at different heights. If their child's head was 2 inches over the top then it's unlikely that they had not changed it from first buying it. When DS1 first went into a HBB he had a Britax Adventure. It got damaged on a plane so I replaced it with a Cybex one. The Cybex one was about 2-3 inches shorter on max height, but I didn't realise until he got to about 9 and it wouldn't go up any higher. This was sold in Germany and Cybex was very big on their "German engineering" credentials at the time! The cheap Britax one was no longer sold and I didn't fancy paying out €100 on a new HBB so we swapped to backless until he was tall enough to sit without.

It was very annoying and I did wish that I had realised at the time. FWIW Cybex now have nice long backed HBBs so it's not a brand thing - I think it was an older model that we had.

Although also worth knowing - due to the shape of some headrests an older child's head will poke out the top and this is OK, it's the position of the shoulder belt guide which is important. The manual should have info about how to line up the headrest with the head position, sometimes you judge it with eyeline/top of ears, sometimes it's distance from shoulder, sometimes the chin is the leveller.

So 9 months ago I posted on here that my daughter was 131cm. She is now 136cm and age 8 and we are still in the HBB. I will be keeping her in till 150cm no matter what other people/friends etc....... say. We recently had to use a taxi in an emergency and she actually said she didn't feel safe with just the seatbelt and that the seatbelt hurt her neck. So she isn't even worried about being in the car seat and friends taking the piss.

Kids will take the piss out of all sorts, it is up to you as a parent to keep your child as safe as possible.

The general ignorance around car seat safety never ceases to amaze me. Not a dig at you OP just people in general. From infant carriers, rear facing and high backed boosters, people just don’t seem to grasp what a car seat is actually for.

OP, the legal minimum height in this country to not use a car seat is 135cm or 12 years old. It is worth bearing in mind that it’s 150cm in the rest of Europe. The children and cars are no different and our roads are no safer so I presume the Europeans just care for their children’s safety more than we do.

It’s not quite as simple as stopping at a specific age or height. The adult seat belt has to fit them correctly, over the shoulder not the neck, they have the sit with their back against the back of the seat and knees bent over the edge of the seat, the lap belt must sit over the lower pelvis not the abdomen. The fit might be different in different cars. For example, my 146cm DD aged 10 has recently stopped using the high backed boosters in my parents car but uses one in mine as the seat belt cuts into her neck in my car.

@0ohLarLar Your high back booster seat probably extended higher but you likely didn't realise.

@ageratum Look at the top of a high back booster seat. What do you see at either side? Head impact protection. What do you think that's going to do if there's an impact from the side?

It's not only the height. An adult has a different bone density, making accidents impacts different.

And the driver and passenger seats very often have features to raise the seat and adjust the seatbelts. You don't have this in the back.

You have front airbags, again not in the back, you would either go straight through the middle or end up against the driver/passenger seat if the seatbelt is not keeping you back.

You assume all crashes are forward/backward, ie head on/rear end.

They are not.

Someone smashing into the side of your car will potentially smash the persons head against the window, having experienced that as an adult in a pretty low speed impact, it's deeply unpleasant and my seatbelt did fuck all about the movement of my head.

I always wonder about the 150cm and car seats. Does that mean shorter adults should be using car seats? What about if they are the driver?

My son is 135cm at age 7 and has loads of room left. I bought one that would last him.

It’s not a target, it’s a minimum.

It is legal to take the seat away at 135 but it’s not the safest choice.

I think we stopped around age ten but I do remember massive peer pressure over it

I suspect my younger kid might be uncomfortable with the booster at a younger age than big sis. She is willowy with most of height in legs, more comfortable in the HBB at 9 (but we have let her go in the middle seat with 3 point belt when giving others lifts).

Younger has much more width to his shoulders and more height in his back, he might well not fit the HBB for shoulder width before he's at height for no booster.

Both seem to like the headrest option, I'd quite like it too for when I'm not driving, looks way more comfortable for a relaxing doze!

My eldest (almost-ten year old) still uses her Britax HBB. She is the smallest in her class (under 135cm) and has never questioned it, and I'd honestly never considered it an issue before this thread. Her two best friends (both taller boys) are still in their HBBs too, although I have noticed a LOT of her classmates getting into the front seat without even a booster seat and I'll admit, I do judge a bit. Lots of dodgy country lanes and blind bends around here, and there's no way it's worth taking that risk for the sake of looking 'cool'.

My children are 12 and 9. My 12 year old has just come out of his booster in the last 2 months. He is 145cm. I followed the guidance below because I know as a short person, that cars aren't designed with our safety in mind. I'm 5ft 2 and the damn car seat belt doesn't fit me properly and honestly, sometimes I feel like I should be able to get an adult booster seat! Now my son is obviously shorter than me, but in the back the belts fitted me better. I can sit safely in the back. But not as the sodding driver!
My 9 year old is over 135cm also, but having checked him, he's nowhere near able to sit safely in the back. So he will be a similar age to his brother I'd imagine.
Also, worth bearing in mind that just because they can sit correctly in one car, doesn't mean they can in another. So if travelling in a different car, I'd just do this quick check below.
BTW I didn't extend rear face or anything. I'm not a car seat zealot. Just a short person who knows that car manufacturers design cars for men!

Ideal placement of the seatbelt and side impact protection.

Backless boosters have no side impact protection.what if you have a tall child who could legally use nothing stage 7? You wouldn’t do that.

My 7 year old is 135cm tall and still in a HBB. Probably until he maxes it out at 150cm. It goes on height so just tell them that.

Incorrect. In most other European countries the minimum height for no car seat or high back booster is 150cm. Cars and the human body aren’t different in other countries! I've witnessed a child's death whilst sat in a car aged 9 with absolutely nothing but a seatbelt.
Nope. Not doing it.

My granddaughter has just stopped using a highback booster. She's nearly 11 and is 142cm tall.

I've witnessed a 9yr old come flying out of a car window (he was sat in the front with no booster seat) and land head first in front of a lorry....
I would much rather my child be laughed at but be fucking ALIVE

See, my DS is 9 and over 135 cm but I still have him in a HBB in our car - although not in family members’ cars as the seat belts seem to fit him fine in theirs. But in ours, without the HBB, the seat belt doesn’t sit across his chest and shoulder, but rather across his neck and chest. He looks too big for a car seat but too short in his torso for an adult seatbelt to work safely.

We plan to change our car this year and I’ll be interested to see how he fits in other cars. He’s definitely in the minority as a lot of his friends had ditched car seats as early as end Year 3.

My dd is nearly 10, and still in a car seat, she's just under 135cm. She accepts her safety is paramount, and it is in her best interests. I do think she is the last in her year (5) to still have the car seat. I'll probably keep her in it til the end of Y6, as I did for her brother, though he his 150cm before then, and she is more petite than him, so maybe she'll still be in it beyond primary.
I think our laws are crap. I had mine RF for the maximim time I could, too.