E350cloud

I am Italian resident In UK and registered to AIRE. I have an Italian Bank account with some savings on it that are invested in bond or others. Once a year they can produce interests that I get in my Italian bank account and the amount is after tax. I don’t bring those money in Uk. Do I need to declare this interest in UK? Do I need to pay tax on them even if I pay tax already in Italy? If is needed to be declared in UK do I need to say the amount Before or after Tax?