I just started looking into this as I have a few properties in the UK and my finances are complicated to say the least. My basic understanding thus far is no CGT up to 2015. CGT on increase in value after 2015 to the point of sale (can't remember if this applies to all properties or only to those properties that are not your home). You have to pay taxman within a certain period of time after selling your home. I think it is 90d. I imagine the taxman will be aware that you have sold your home given that Land Registry/Local Council will need to know as well as potential reporting requirements from 3rd party agencies. It probably will not cross their radar initially but it may do in the future. I have just been contacted by the taxman suggesting I owe him tax (I don't). I can only assume he got his information from an enquiry I made of my local council about 3 years ago. This is possibly linked to a phone call my sister received a few years ago asking if I lived at her address (I don't but I use it as a correspondence address). The UK system may be slow but there are no guarantees that they will not find out at some point. If you have cut all ties with the UK then this probably will not matter.