I can’t open a bank account because my visa/residence permit expires soon.

With the submission of your application file (in Berlin) or request of an appointment (in Potsdam) your visa/residence permit is automatically extended until the Immigration Office takes a decision about your application. In Berlin SERS receives a confirmation mail for each student with an issued case number stating that the student remains legal on the territory until the Immigration Office takes a decision. This confirmation mail can be requested by the student from SERS and be shown to third partis, such as bank institutes.

Banks that do not accept this email confirmation are doing wrong as they must accept an official confirmation issued by the Immigration Office stating that you are legal. The Immigration Office insists on the fact that the banks should read and accept their mails, otherwise they can contact the Immigration Office confirming the information. SERS advice also to look for other banks in case of doubts as each bank and even its branches decide individually.