Louise Brockbank

Hello, I own a home which I originally lived in but have since let out after moving into my partner's home (which is entirely in their name but I do contribute to the bills). If I were to sell the house I own but go onto the deeds/mortgage with my partner am I still liable for CGT? Alternatively if I sell the property but do not effectively buy in with my partner am I still liable for CGT with it being the only property that I own? Thanks