What is a blocked account?
A blocked account is a (savings) bank account created in the name of the aspirant, to which a certain minimum balance needs to be transferred. Currently, this minimum balance is set to be 8,640 euros for the duration of one year. Once the amount is transferred, it will remain blocked until the student reaches Germany and activates his account.
A blocked account is one of the ways by which you can prove to the German embassy that you have sufficient means to support yourself during your stay in Germany. Thus, in general, blocked account confirmation is an important document which you need to secure before going for the Visa Interview (although it is not a mandatory document since you can prove the that you have sufficient finances by other means).
Note: The amount to be transferred to the blocked account doesn’t include the college tuition fee. It is only for the living expenses in Germany. If your college has a tuition fee, you need to produce another document as a proof of tuition fee payment.
Another stipulation that comes with the blocked account is that you will only be able to withdraw up to 720 euros per month while you are in Germany. This amount would suffice for your living expenses per month even if you live in expensive cities like Munich, Frankfurt, Hamburg etc.