Selling family flat abroad, tax?

Hello, I am about to sell a flat in Poland. In 2012, my mum transfer the ownership to me before she passed away. I didn't even think about selling it as my grandmother had lived there - until last year (she passer away). Now, as I don't plan to live in Poland (I am permanently live in UK since 2011) I would like to sell it. Could you please help me figure out if I will have to pay any tax if I sell it and how to calculate it? That flat was in my family before I was even born. My grandparents passed it to my mom and the she passed it to me, I have no idea how much it used to be worth etc, only how much its worth now based on general market price per square meter. Could you please advice?

Hi,

When calculating the Capital Gains Tax due on the sale of an inherited overseas property, you would first need to establish the market value of the property on the date on which you inherited it.

CG16330 - Assets: principles of valuation: meaning of market value

You may also find HMRC's Capital Gains Tax on Property calculator helpful:        

Tax when you sell property

Thank you.