I can’t cope with the tantrums!

[WhenIsEnough]

My pre-teen (12) swears at me, refuses to go to bed and threatens to not go to school. It’s never ending. Any advice?

Pick your battles.
Don't worry about things that don't matter.

Make sure you don't put yourself at the bottom of the family priority list/hierarchy.

Try to reconnect with them. Find something you can do together.

Driving or walking is a good place to talk as you aren't looking at each other.

Thank you. I am finding it very hard to cope.

Lack of respect has repercussions.. WiFi is switched off here. Phones don't get topped up and my purse stays shut..
Suggest fines for non attendance will come from pocket money or dc's savings.

Yes, I use Wi-Fi as currency too.

Presuming you are in the UK, then it's either already the holidays or it's the holidays very soon so I'd forget trying to have a bedtime.

Dd 15 has recently refused a few days at school.. So today she is holed up in the school library all day catching up!! I am getting begging messages to go save her!!
Aibu to be a bit smug??

I would not tolerate any child swearing at me. They have to learn that bad behaviour will not get them what they want.

Start by getting a lot tougher. No way would I put up with a child swearing at me.
Remind her who pays for her food, her clothing, her entertainment.
Stop doing her washing, let her cook for herself until she learns to speak respectfully.