Hope this makes sense, very upset so not sure whether it will 😟 MIL for the sake of this post is my partners mum, we aren't married.
Background - partner has been living with MIL for around 3 years as she is ill mobility wise and needs a lot of support in doing things, 2 months ago she moved from an upstairs 2 bed flat into a 1 bed downstairs so she has needed less support since then. She really needed a downstairs flat and has been waiting a while, so although she essentially made her son homeless/not have a room, he accepted the reasons behind her moving. Partner had been staying over at mine 1 night a week, 2 at weekends when my 4yo son is at his dads, but since his mum doesn't really need him much anymore we decided it is best for him to move in with us instead of sleeping on the sofa there. Last week I started university and my housing benefit claim changed when I became a student due to student finance, so it was already changing to a smaller amount- we decided just to cancel it altogether.
I called today to update that he moved in yesterday and they asked for his previous address for council tax purposes - they had the council tax letter in the old 2 bed property under both names and simply called to change the address when they moved. Hes been paying the same amount of council tax to his mum for the new property as he's always paid, knowing he'd moved it over, but it turns out after he did this she called and took him off the claim. This means it looks like he never lived in the new property and moved out when she moved and they are now suggesting that I have been claiming single person discount and exemption when I shouldn't have been. I can't believe she has told them this - if they decide that he has been living here (even though he actually hasn't and only moved his things in last night and obviously hasn't moved any bills etc over yet!!) My income support claim and child tax credits claim from 2 months ago will be affected and I'll be made to pay it back.. just so MIL could get a single person discount. The worst part about it is that he was paying her share too so it's not even that she needed the discount - she didn't pay anything out of her own money in the first place!! 🤔