SOME P7 pupils received their transfer test results on Friday - one day ahead of the majority of children.
Children who sat the GL Assessment, run by Post-Primary Transfer Consortium (PPTC), at Antrim Grammar School got their results amid a "mailing error".
It is not clear how many children received their test results early.
In a statement from the school, released through the Education Authority, it said that "due to a mailing error some parents will have received their child's GL Assessment results a day early".
"As per usual guidance, we will manage any questions or concerns relating to GL or AQE results on Monday 6 February."
Thousands of children across the north who sat the tests run by the AQE or PPTC are due to get their results on Saturday.
Post-primary transfer tests are used to select pupils, aged 10 and 11, by the majority of grammar schools in Northern Ireland.