/ Banking tax Procedure in Poland
it's so called "podatek belki" it was itroduced only a couple of years ago...
There is one flat tax rate (19%) on capital income. It includes: selling stocks, bonds, mutual funds shares and also interests from bank deposits
It is simple if you have a bank deposit of some sort and receive interests, you have capital gains and you must pay the tax.
a bank is a so called "płatnik" (just like an employer that pays the downpayments on the income tax for the emploees)...
urząd skarbowy receives each month the money diractly from the banks... I'd say it's more convenient this way and probably it also serves to reduce the moral hazard... :)