Logging into data portals for the tax authorities will soon only be possible via ”eHerkenning” and DigiD

From 1 October 2023, you can only log in to the Tax and Customs Administration’s data portals with eHerkenning (eH3) and/or DigiD (with the DigiD app or DigiD with SMS verification). At the moment, login is still done with a user name, password and the SMS verification offered by the portals.

Source Taxlive