A Blocked Account (“Sperrkonto” in German), works as a proof of financial resources for people that are planning to apply for a visa/residence permit for their stay in Germany. The main groups of people that are required to have a Blocked Account are students, au pairs, language students, job seekers and basically everyone whose stay in Germany is not supported by some external sources such as salary, scholarship, etc.
The money transferred to the Blocked Account is initially “blocked” until the account holder arrives in Germany. Once the account holder activates their Blocked Account, they start receiving the monthly amount.
The German foreign authority makes monthly payouts a requirement instead of a payout of the total amount in one go to ensure that the person coming to Germany is financially sustained throughout their stay in Germany. You can find more information about this on the German foreign office website.
The Blocked Amount requirements of local embassies might differ from the general requirement, and they are also affected by the details of your own visa application. Therefore it is important to consult with the embassy handling your visa application to ensure that you satisfy the local criteria.
As of Jan 2023 the standard monthly blocked amount required by the German Federal Foreign Office for university students is €934 per month.