For some banks, when customer’s use 3rd party payment processors such as Trustly, the bank will provide additional security measures through the use of a virtual account (VAN) or a tokenized account number (TAN).
Use of these numbers is an additional security measure that a financial institution can choose to use to mask the actual consumer account number. Instead of transmitting the consumer’s account number to Trustly, and other 3rd party companies, they create a virtual account that corresponds to the consumer account. It’s the virtual account that is transmitted.