From when is it possible to register a change of address?

Within one municipality? We are moving from municipality A to municipality B and the mayor of A absolutely refuses to release our child because the municipality invested a few million in renovating the school(s) last year and this year. The school in municipality B would gladly accept our child - we have already had discussions. For them, none of this is understandable.

No, not within one municipality. But from city A to municipality B, so basically like in your case. And if you contact the school authority? I don’t know what the legal chances look like, but in the end there has to be a solution that is acceptable to all parties.

Within one municipality?
We are moving from municipality A to municipality B and the mayor of A absolutely refuses to release our child because the municipality invested a few million in the renovation of the school(s) last year and this year.

I can understand, Mayor A is under a lot of pressure as to why he wasted the funds on renovating the school instead of building specialist accommodation.

I assume that you want to avoid your child forming friendships that will have to be broken off again after a year. Or is there another reason? That would, of course, be unfortunate, but here are a few points to consider: if your child has already made friends here in the daycare, kindergarten, or surroundings, then there will be some tearful goodbyes anyway. Whether they are separated this year or next, does that really matter? The kindergarten and neighborhood friends often see each other again in first grade, so these too would be separated by enrollment in B now. So if municipality A or B refuses, it wouldn’t be nice, but not a catastrophe that would force you to move again in between. Perhaps starting school – and thus the big step into life – in the old community with "old" friends is even somewhat more helpful. Next year after the move, you can enroll your child in the new school quite calmly – if your child is clever, you are just worrying unnecessarily.

I assume you want to avoid your child forming friendships that they have to break off again after a year. Or is there another reason? That would of course be unfortunate, but here are a few points to consider: if your child has already made friendships here in the daycare, kindergarten, or neighborhood, then there will be some tearful goodbyes anyway. Does it really matter if these are separated this year or next? The kindergarten and neighborhood friends often see each other again in first grade, so these friends would also be separated by starting school in B now. So if municipality A or B refuses, it wouldn't be nice but it wouldn't be a catastrophe, requiring you to move again in between. Perhaps starting school and thus the big step into life in the old municipality with "old" friends is even somewhat helpful. Next year after moving, you can calmly register your child at the new school – if your child is smart, you are just worrying unnecessarily.

So all our children go to kindergarten in municipality B, where we also work. Currently, the older one would attend school in A, then go back to B after the house is finished. Changing once is okay, but we want to avoid doing it twice.

Please google the words Elternwille, Schulgesetz, and your federal state. If you find anything, write to the school authority with a carbon copy to the formally responsible school that it is your declared parental will that the child be enrolled in the school at the place of residence. Further justify that you are already working there and that the child has attended kindergarten there. You also commit to ensuring that there will be no non-illness-related absences. The receiving school has stated that there is space available for the child. If this is not possible, your child will stay at home until the move. However, you really do not want that. Important: Write the letter very friendly but clearly and send it by registered mail/with return receipt. You will be invited to a meeting at the school authority very quickly, where you explain this again kindly but firmly and do not allow yourself to be persuaded otherwise. The arguments must be repeated like a mantra. And the phrase "our declared parental will" in every second sentence. So far, this has always worked. Important: very friendly but tough on the matter.

Oh yes, I almost forgot: you should bring the building permit and a certificate of commencement of construction to the meeting. (not in the letter!!!!!)