It is the tax payer's job not to 'forget' about the earned interest.
...yeah...and if they had that in Poland, everyone, but everyone would declare their interest on their tax form and pay.....dream on.
What about foreign nationals like me who have money on deposit - I don't have a Polish tax form to complete. So you're going to tell me now that I need to declare interest on my savings to my taxman - year, right.
Tax on interest has been in existence for a good number of years - live with it.