why does the bank send the same questionnaire again each year

The bank repeats its customer due diligence, not its curiosity

The bank must establish annually that its customer due diligence is still correct. That due diligence — who the enterprise is, who the ultimate beneficial owners are, where the funds come from — is not a snapshot that you deliver once and that remains valid thereafter. The bank must be able to demonstrate that its picture of the customer is current, and that means: asking the same questions periodically, even if nothing has changed. That is why the question about the ultimate beneficial owners comes up every year, even if the UBO structure has been the same for three years.

What does differ per bank is the customer's risk profile, and that determines how often and how thoroughly. A customer with a higher risk — think of a PEP relationship or a structure with multiple foreign entities — receives more frequent and more detailed due diligence than a customer with a low risk. This also explains why the question of whether a director is a politically exposed person sometimes comes annually and sometimes only once every few years. The questionnaire is thus not repeated arbitrarily, but the rhythm is determined by the bank, not by a fixed statutory annual term that is the same for every customer.

Where that is stated in the Wwft: customer due diligence

The obligation to conduct ongoing customer due diligence follows from the Dutch Anti-Money Laundering and Counter-Terrorism Financing Act. That act obliges the bank not only to conduct due diligence when entering into the relationship, but also to continuously verify that the previously recorded data are still current — and to request that data again when that is uncertain. Other chain questions, such as those on data from the Trade Register or on sustainability reporting under the CSRD, each have their own rhythm; the annual bank question comes specifically from this Wwft obligation.