A legal opinion by the Tennessee attorney general said school districts must give a variety of student data to approved charter schools and their operators.
In the opinion Wednesday, Attorney General Herbert Slatery wrote school districts with policies that ban releasing the information can only do so temporarily.
It said districts must first give parents a chance to opt out and then amend their policies to release the information, which ranged from students' contact information to their participation in sports and activities.
The opinion requested by state Education Commissioner Candice McQueen came after Nashville and Shelby County, including Memphis, recently refused to release the information to charter schools operators.
Charters have used the data for recruitment and marketing purposes but may not share the information with outside parties.