Sofortüberweisung is subject to the guidelines of PSD2 and therefore receives an additional authentication step, the so-called second factor. When you select Sofortüberweisung as the payment method in an online shop, you log in with your online banking details as usual. The classic login and password is one “factor”, it must be supplemented by a second one that is not physically owned by the customer.
With the second authentication step, which can vary depending on your house bank (e.g. fingerprint or TAN procedure), you confirm that we have access to your account so that we can make the payment. Only after this additional confirmation of the second factor can you complete the payment process.