This is covered by the Privacy Act 1993. Your old school can’t tell a new school information about you unless giving that information to the new school was one of the reasons your school got that information from you in the first place (this includes information about when you were enrolled at the school), unless you agree, or one of the other grounds stated in the Privacy Act covers it. Schools can tell new schools if you are currently excluded or expelled and why, but they can’t tell new schools all about you, or pass over your school file, unless you agree.

You have the right to know what one school has told another school about you. This is personal information about you, and you can ask what has been said, under the Privacy Act. Even if the information is not written down, you must be told what was said.