Beste antwoord door Thomas NS
When you log in to your MijnNSaccount and you go to 'Mijn Producten' in the left option menu. Then, at the bottom, you'll find the option 'aanpassen of uitbreiden'. If you click on this button, you'll see your contract details. Next to your bankaccount number, there is the option 'Wijzigen'. If you click on this, you can change your bank account yourself.