Accreditation

The Metropolitan International School is a state-approved private school based on the Schools Act of the State of Hessen and a registered Cambridge International Centre.
MIS is an international school, following the German law. The school combines the advantages of approved German school leaving certificates, with the typical features of international schools. These are a full-time care, a high level of individualization supporting the learning process.
We offer a purely English-speaking curriculum from the world-renowned Cambridge Programme, for international families wishing to ensure continuity in their children's education.
The second option involves meeting the combined requirements of the Cambridge International Examinations and those of the German state of Hesse.
With this special curriculum, the MIS offers not only an internationally competitive education in the English and German languages, but also ensures that German children will fulfill all requirements of compulsory education.

The recognition of the Cambridge degrees IGCSE and A-Level

For the competency of approval authorities, the so-called “place of residence principle” is usually applicable in Germany. This states that the question which public authority is in charge of a certain request depends on the place of residence of the requester.

(http://www.kmk.org/zab/anerkennung-im-schulbereich.html)

As a consequence, the place of location of the school is not relevant, but the place of residence of the student. For Hessen, the acceptation is regulated in the following official register (page 286).
You can request the acceptation here 
For the federal state of Baden-Württemberg, you have to contact the following agency

For the recognition of the A-Level, the situation is different:
The German universities are responsible for both the decision about admitting a student and for the amount of the acceptation of course achievements. (http://www.anabin.kmk.org)
This means that, at the given time, everybody must ask and find out individually and explicitly which school courses must be completed for which university study course at which university.