Full definition
Named after former finance minister Marek Belka, introduced 1 March 2002. The 19% rate covers: interest on deposits and savings accounts (withheld automatically by the bank), interest on bonds (outside IKE/IKZE tax-advantaged accounts), dividends from equities (withheld by the broker), gains from investment funds (withheld by the TFI on redemption), gains from listed securities (self-reported in PIT-38 by 30 April). Exemptions: IKE and IKZE retirement accounts — gains are tax-exempt if withdrawn after age 60/65; specific Treasury bonds held through IKE. Non-IKE Treasury bonds are taxed normally.
Formula
Tax = 19% × gross gain (interest, dividends, sale gains)
Concrete numeric example
100,000 PLN deposit, 6% annual rate, 12 months → gross interest 6,000 PLN. Belka tax = 19% × 6,000 = 1,140 PLN. Net: 4,860 PLN. The same deposit inside an IKE (if available): 6,000 PLN net — but funds locked until age 60.