Students across the state will have their Higher School Certificates reissued, after the Education Standard Authority accidentally sent out thousands with the wrong date.
Instead of being listed as December 2018, they were dated 2017, with Education Minster Rob Stokes ordering the blunder be fixed immediately.
"I understand it was an administrative error within the organisation," he told the Hit Newsroom.
"Our students show incredible diligence when undertaking their HSC exams, and expect the independent authority charged with administering those exams to demonstrate the same level of care and excellence."
Shadow Minister for Education Jihad Dib said the mistake was a massive "disappointment" for the 70,000 students affected by the blunder.
"How can they and their achievements not count with this government?” Mr Dib said.
“This Government can’t make right the sense of disappointment and neglect but they can re-issue properly valid certificates.”