School chiefs are in the dark over how many children are educated at home.
Education Minister Michelle McIlveen said the number of homeschooled children was rising, partly due to religious beliefs and dissatisfaction with the current arrangements.
Bullying has also been given as a reason why some parents are choosing to educate their children outside the system, alongside special educational needs, mental health issues and philosophical reasons.
But the Education Authority admitted it did not know how many kids were involved.
DUP minister Ms McIlveen is coming under pressure to set up an official register of youngsters outside the system.
Alliance MLA Connie Egan called on her to do more for homeschooled kids.
She said: “There should be a record of where every child is being educated, to ensure they are making the progress commensurate with their age.
“It appears the Education Authority does not even know how many children are being homeschooled.
“I would urge the minister to introduce a comprehensive register of all home-educated children.”
In recommendations to the Education Authority, the Northern Ireland Commissioner for Children and Young People said the minister had responsibilities to all children, not just those in the system.
Koulla Yiasouma argued that the state’s responsibility was “not only confined to schools, but wherever children are being educated, including in their home”.
Ms McIlveen said that while the Education Authority did hold records on children who had de-registered from the schools system, it did not have sufficient detail to explain why the number had increased.
She added: “If a child has never attended school, there is no legal requirement on parents to register with the Education Authority.
“The responsibility for a child’s education rests with the child’s parents, and parents may secure their child’s efficient full-time education either at school or outside the school’s environment.”