How can I make changes regarding American Express, e.g., bank details, address, clearing name, Etc.?
The first rule is to contact American Express directly with all change requests!
If you use the American Express online service (https://www.americanexpress.com/at/services/online-services.html), you can log in and change the desired information by clicking on “Manage Account.”
Alternatively, you can call American Express at +49 69 9797 2222 with your Amex contract number (VU).