Dying in Poland - Inheritance tax ?

Merged: Inheritance tax on a property left to a grandchild. What are the laws in regard to selling/renting it?

My grandfather resided in poland. He is polish but has dual nationality as he lived and worked in the UK for over 40 years. He passed away 2 weeks ago and left his apartment to me in his will. This was authorised by a notary. The property is worth approx £35k . As he does not want any of his children to have any claim on it, he had the notary write a letter of 'donation' to me. What are the laws if I were to rent or pref.sell the apartment? I am british and live and work here so completely clueless to how it works.

My grandfather seemed to think if I were to not sell for 5 years then I would avoid the 20% inheritance tax and his children would not be entitled to anything. I really dont want to rent it out for 5 years!

The poles are very strong on there laws you seem to already know that you would have to rent it out for 5 years so to avoid the inheritance tax and not allow a red cent to his children there are no loopholes it might depend upon what voideveship he lived in if you could disclose where he lived ie near Warsaw, Krakok, Gdansk, Bialystok or Lublin it could change thing if he lived in a small village