Transfer of equity/taking name off mortgage

[MrsMime]

Does anyone know how this process works?
My DP is still on the mortgage with ExW and has continued paying into it since they split up and he moved out.
Me and DP are now in a position to buy a house together but, because he is still on the mortgage at his old house, he would have to pay extra stamp duty which we can't afford so he would like to be taken off the mortgage at his old house but we don't know how that will affect his equity share (which he obviously wants to retain to this point) and how gets the process started.
Any advice would be appreciated. I will also post this on Divorce board.
Thanks in advance.

Does his ex not need to see whether her credit score is good enough to take on the full mortgage? The bank may not let his name be removed if she can't afford to pay it herself

Is he divorced? I only ask as part of the divorce process usually involves the division of assets.
So exh and I went through mediation to work out what was a fair split of equity.
If they can do it between themselves then great but mediation does help and is vastly cheaper than going to court.

His exwife will also need to see if she can get a mortgage in her own name in order to buy him out. If she can't then again this affects the process especially if they have dc's.
I know when I was going through the process the mediator said that if I couldn't get a mortgage in my own name then most likely exh would have to wait to get his share of the equity until I either sold the house in the future or my youngest turned 18 whichever came first.

Each case is so different so it's hard to give exact processes and I only really have mine to give in context.

Luckily I managed to get a mortgage in my own name and so exh is now off the title deeds and he now has his lump sum of equity. The whole process for me took around 9 months of applying for a mortgage/mediation and then exh was terribly slow and replying to forms etc but it could be done a lot quicker than that.

OP I've posted on your other post, you're in for a long, expensive, and very bumpy ride.

You need to put the brakes on buying a place together until he is disentangled from his existing liabilities. There is so much more to this than stamp duty.

Have you taken into account that his existing mortgage will count against him for affordability, even if he doesn’t make any payments at the moment?

Can his ex afford to take him off the mortgage - in terms of earning enough and bank affordability, rather than practically?

Sadly, I don’t think there’s any way this will be resolved quickly. It tends to be an utter mess. He needed to sort this before you were ready to move, really…

But he’s going to need legal advice on how to keep his equity. Most banks won’t allow you to be on the deeds without being on the mortgage, so his ex would need to be able to buy him out, or sell, in most cases.

Thanks all - this is very helpful.
She is able to take on the mortgage herself. There is very little remaining and I believe she is moving in/buying new with her DP although I don't know for sure about that.
We have spoken to an FA (he is the one who flagged up the extra stamp duty etc). I want my DP to sort finances before we move forward - I perhaps didn't make that clear in my OP - and this is the first thing to do which is why I was asking for specific advice on this.
Thank you to everyone who has responded.