CGT for unmarried couples and sole ownership

My partner and I jointly own a home. We are not married and are about to pay off the mortgage and transfer it into my sole ownership. If he later buys a house and has sole ownership with a mortgage in his name, but we both live there and then sell the house I have sole ownership of, what are the implications for both of us in terms of CGT?

Hi,
We cannot provide financial advice.  
Private Residence Relief is applicable for the period that a property was your main residence and needs to be calculated to determine if there is a capital gain chargeable to tax. You can see guidance here:
HS283 Private Residence Relief (2024)
There is also a capital gains calcualtor below which leads on to reporting and paying the capital gains within 60 days of the completion date.
Tax when you sell property
Thank you.