St Mary's School pupil Lily Hackett, 12, has auditory processing disorder and it is hard for her to hear when there is background noise in a room.
A special hearing device was given to Lily by the ministry, making it easier for her to listen to her teacher in class.
Her mother, Rose, was initially told by the ministry the device was specifically calibrated to Lily and would be no use to anyone else so she would be able to take it with her to Australia when their family moved in February.
However, Lily's school was told the device would have to be returned.
Ms Hackett said it took more than a year to obtain the device and she did not want Lily to have to go through the whole process again when they moved to Australia.
"These are needed for her education. I can't express in words how much this device actually means to Lily."
She said the school's principal, Mike Brosnahan, gave his blessing for Lily to take the device and Ms Hackett even offered to pay for it.
Ms Hackett did not understand why she had received such mixed messages.
Ministry south leader Nancy Bell said the New Zealand government-funded device would be sent back to the supplier for service and maintenance before it was reissued to a new student.
It was possible to transfer the device between schools within New Zealand but not overseas.
The device could not be bought either because it was Crown-funded.
"We have apologised to the family for the miscommunication and would encourage them to talk with their child's new school in Australia about how assistive technologies are provided to ensure any equipment is compatible with other systems and technology in use in the new school setting," Ms Bell said.