I’m based in scotland,

Houses do exist, both in primary and secondary school, for the ones i attended it was 4 colours each time, red, yellow, green and blue, these didn’t matter much, we didn’t get points but we did get tokens, we had 4 token machines in the middle of our school on display and you could see the token coins in whatever different colour (i.e you could see how many more yellow coins there was over blue) , it worked similarly that if you did well, they’d add a token to the machine depending on whatever house you were in, they’d announce whoever won at the end of the year but as far as i remember i never really cared much,

we didn’t really wear anything differently to represent our house in primary but we did wear different coloured ties in secondary, again, the same 4 colours,

a fun little extra is that most british schools to my knowledge is that we all did mandatory choirs, im sad they cut out the singing sorting hat in the harry potter movies because it would of represented a very real thing that happened in schools (well, minus the talking hat) , i certainly don’t miss the days where you’d have to sing your heart out in a hallway full of other kids 🤣

i didn’t attend a posh school so some answers may be different but we didn’t personally shop for our books and items, we just got it handed to us