if there is a minimum time then it'll be 2 years but i'm pretty certain that's only if it's not your main residence. My situation is I have a falt that I lived in for about 18 months which I now rent out. My main residence is the house I now live in. If I want to sell my flat and have no CGT, then I would have to 'move' back in for around 6 months. i don't have to physically live in it but all my post, bills etc, would have to be registered there plus council tax etc. I think i'd be liable to CGT because I have another home, i.e the one I live in now. Basically, if she lives in the previously rented one and it is her only home then I think she won't be liable. Hope that makes some sense.