May my bank disclose my balance to third parties?

Banking secrecy is not explicitly enshrined in a Dutch law like in Switzerland, but follows from bank-client contract (Dutch Civil Code 7:401 duty of care + GDPR basis). Banks may NOT share your balance, transactions, credit history with third parties without basis. Statutory exceptions: (1) Tax authority: annual balance reporting + on targeted investigation transaction data (AWR Art. 47/53). (2) Justice: targeted demand with court order. (3) FIU (anti-ML): unusual transactions (Wwft). (4) BKR/Dutch Credit Registry: credit registration with customer consent in general terms. (5) CRS/FATCA: data exchange with foreign tax authorities. What is NOT allowed: sharing with partner (even within marital community accounts stay separate), with employer, with other family, with commercial partners. For PSD2 + payment data sharing (open banking): separate explicit consent + revoke option within 90 days. On unjustified sharing: Kifid complaint + AP complaint + civil damages claim. Example 2023: ING fined for sharing balance info with external bank-comparison tool without customer consent.