Buying house from ex

[Frendcheeeeska]

Looking ahead to buying my ex out of our current home.
We have 3 small children and have been separated for over a year (never married).

When we bought the house I was on mat leave with the 2nd pregnancy (and was pregnant with the 3rd) and had bad credit due to a Covid job loss that meant I’d used my credit cards to survive and negatively impacted my credit rating. Due to this we decided to buy solely in his name - I’m not on deeds or mortgage.

Despite being on a decent wage he had little savings and I had more so I put in about 70% of the deposit.

Within weeks of moving into the house, i found out he was cheating so we separated.
He only ever contributed towards two mortgage payments.
Due to 3rd child, being on mat leave and not great credit I was unable to buy the property off him.
Now I’m back at work and starting to think about buying from him as I dont feel secure that I’ve made all mortgage payments, repairs, maintenance etc and it’s not in my name. As well as the fact he has recently announced his engagement to another woman.
i have spoken to him and he has agreed that if I can get a mortgage he will take no equity in lieu of child maintenance and sell to me at whatever the mortgage balance sits at as I’ve paid all payments, as long as I give him his 30% that he put into the deposit at the time of purchase.
I have only just started back at work and savings are low due to having paid for everything while on mat leave with no child maintenance off him.
i also own another property so will have additional dwelling supplement to pay as well I think.
my credit rating is improving but still at poor because I relied on overdraft that last 6months of Mat leave.
the fixed rate on the current mortgage ends in 2027 and I know by that point my savings, credit rating and wage will be good enough for me to buy the property off him.
my questions:

1. will the bank (or anyone) query me buying it at the mortgage balance value when I’m not named on deeds or mortgage? If it will be an issue is there anything I can do now so it’s less complicated when I do come to buy? First two mortgage payments made by him came from his bank account, rest have all been from mine.
2. how will his marriage impact things (they’ve set a December 2025 date)?
3. im not in a position to buy now but could maybe buy in early 2026 before our fixed rate deal ends. This will put a financial strain on me but I would do it if it’s the wiser thing to do (I’ll have to borrow on my other property to pay off the ADS as well as early repayment charge).
4. while waiting to be in a position to buy off him I only have his agreement via text messages, will this be enough proof should anything change or is there a legal document I can get to ensure he upholds his end of the deal?

please no judgement about 2 properties, first property is in a area that’s a 6hour round trip from dad and kids are not being allowed to move from current area to uphold contact. I’ve already looked to move back with the idea of starting over.
selling my rental also difficult due to not wanting to put family currently living there in difficulty (but if that was my only option I would have no choice).

No advice on the legalities and it being in his name etc but I do know from a family member that bought their council house that if you are buying under market value you can often use the 'discount' as a deposit, their broker told them that this was extremely common for council house discounts, parents selling cheap to kids, landlords selling to tenant for a discount etc. so you may not need to worry about saving for a deposit it would just be stamp duty and fees you'd need. I would say that the sooner you can get it sorted the better you will feel and the less chance he has to change his mind.

Definitely would recommend sitting down with a broker and laying this all out, you may find that you are in a better place than you think. All the bank cares about is the likelihood of getting the cash back, I have just bought and am in my overdraft by £1500, it was never an issue and it meant I could use all of my savings for the deposit and solicitors fees rather than paying that back and waiting to save it back up again to move, my broker said that as long as there were no recent late/missed payments and no CCJs most people aren't as badly affected by their credit score as they think, mine wasn't great and I just didn't get as good of an interest rate as I could have but I just made sure the repayments were affordable and will focus on mending it before remortgage.

Not sure I understand the bit about your other property though, do you mean that you have enough equity to take out of the other property to pay for this property and stamp duty/early repayment change outright? and that the mortgage you will need will be on the buy to let? or do you mean that you will need a mortgage for your current house and a smaller mortgage on your rental to cover these fees? If you have enough in the rental I would look to remortgage this for as much as possible to be mortgage free in current house. A decent broker really will give you all the options and may propose a solution you aren't aware of, hope you get sorted :)