This question already has an answer here:
Can students transfer from one school of witchcraft and wizardry to another?
I am aware that there are many schools of witchcraft and wizardry and I'm aware of the fact that they enroll students based on their geographical range, as well as the decision made by The Educational Office of the International Confederation of Wizards, when it comes to foreign and overseas students.
But what if one student, who was learning in Hogwarts, decides to move to Durmstrang Institute? Is this allowed by the Ministry? Or is there a syllabus difference that makes transfers cumbersome?