Re house it's a bit more complex
Both brothers bought house together in boom in 2006
No deposit put down, interest only mortgage, house low about £30k negative equity
Not sure why but my now husband moved into house in 2006 whilst his brother chose to live with friends and then emigrated.
Mortgage was a tracker so really low ie started at 500'and over years reduced.
Husband (all before married him) paid mortgage and rates and bills (obviously) and did some renovations.
He didn't pay market rate rent just mortgage.
Moves out 2015.
House rented for a year.
Brother returns and moves in. Pays low mortgage for a year (like husband did)
Year later brother sends detailed spreadsheets to husband charting mortgage interest rate from 2006 know and mortgage paid.
Brother works out that my husband (comes from our joint account) needs to pay mortgage and council tax on house for x number of years in order to ensure equal benefit.
I understand need to have equal benefit but I haven't seen spreadsheet or how it was worked out.
It's also likely that brother may end up living there as long as husband did which would mean he's actually had more of a benefit.
It's the lack of communication about this which annoys me. I agree there needs to some arrangement and happy to pay but I've no idea how been worked out or for how long. Directly affects me as out of joint account.