must I inform them if there is a new director at my company

Management changes must be reported to the commercial register; the bank follows from there

Yes, a new manager must be reported, but not directly to the bank as the first step. The statutory reporting obligation lies with the commercial register of the Chamber of Commerce: every change in managers is data about the company that is recorded. Once that registration has been processed, the bank is the party that picks this up — banks check periodically and upon signals whether their client file is still current, and a management change is precisely such a signal.

In practice, the bank then asks for an extract on which the new manager already appears, and sometimes for an identification document of that person. If you do not yet have that extract, the answer to the questionnaire is not "no" but "not yet available" — with the registration at the Chamber of Commerce as the next step. This often immediately touches two other questions in the same list: who are the ultimate beneficial owners of the company, because a new manager is not automatically also a new UBO, and whether that manager is a politically prominent person, which the bank wants to know separately because adjusted customer due diligence applies to that. You resolve both questions with the same source document, not with a separate declaration.

Where this follows from: Commercial Register Act and the AML Directive

The basis is the Commercial Register Act 2007: managers are one of the data points maintained for each registered company, and a change in this must be reported to the commercial register. The bank itself acts on the basis of the Directive (EU) 2015/849 on the prevention of the use of the financial system for the purposes of money laundering or terrorist financing, which requires banks to keep their customer due diligence current — a management change is a reason to repeat or supplement that due diligence. Which supporting document the bank precisely requests in this regard varies per bank and is not stated in the directive itself; that can be seen from the bank's portal. If the change coincides with an address change or a new shareholder, the question about the bank relationships of the company often appears again in the same list — that is then not a new question, but a check whether the file is still consistent.