User blog comment:JayeMalik'/Ministry of Magic Employees/@comment-24344137-20170902000247/@comment-24894829-20170904022848

It isn't impossible to keep track of each child with magic, because the Book does that automatically on its own (for people within the Great Britain and Ireland borders or United Kingdom and Republic of Ireland borders, whichever you would like to go with, like Yorkie said, or whoever the Book and Quill want to attend Hogwarts). Since it would be based off of after they show a significant sign of magic, that math would be a bit off, since the first signs of magic could be anywhere from five to eleven (the popular range seems to be six to eight), so let us just say that it's at seven. That would be about five hundred people, or at most seven hundred people. If all of their names are listed in the Book, the process to sending a letter out (once a year or every other year, whatever would be decided) would be almost the same as it would be when McGonagall sent letters out to incoming first years, just there would be more. I'm in no way saying that they could track everybody in the world, which would certainly be more of a problem and also wouldn't be their problem to deal with. Bad things can still happen, but the government should be able to catch them like a functioning government should, I think. *Shrug*