The lender is unlikely to agree to the changes that you suggest. You will either have to pay off the old mortgage with a new one (there's plenty of equity in the property so this shouldn't be a problem) or keep the existing mortgage and put the agreement about who pays what, who owns what, and so on in writing (you should both sign two copies, one for each of you, so that you've each got a record of what has been agreed). If taking the latter option, the mortgage provider can still hold either of you liable for the mortgage payments.

I have been seperated from my wife for some time now, although we have stayed in the same property, which we own as joint tennants, and still share the mortgage payments.

I have decided to move out this year and make a new start. I have agreed to her staying in the property for up to 2 years to allow my son to settle into secondary school. At the end of these 2 years, she will either buy me out, or the house will be sold and the equity split.

The house is worth approx £400K, with an outstanding mortgage of approx £80K. We have agreed that she will take on all of the mortgage, and we will change the house into tennants in common, with a 60/40 split in her favour. to reflect the added mortgage burden.

Questions: Can she retain our current mortgage deal and simply remove me from it, or will she need to remortgage (we have a 10 year fixed deal, and she could be liable for large early payment penalties)? Secondly, will this allow me to apply for a mortgage in my own single name, without reference to my existing property, or will I still be liable to my existing property, should she be unable to maintain payments on it?