But a Qualifications Authority investigation found an 11 per cent achievement rate at level one and 33 per cent achievement rates at levels two and three.
Ministry of Education deputy secretary of regional operations Nicholas Pole said schools were legally required to ensure examinations were assessed correctly.
Moerewa principal Keri Milne-Ihimaera said it was unbelievable that students had waited months for the audit's results. Asked about the variance between NZQA and teachers' marking, she said some students failed their qualifications for the want of a few credits. However, the school was prepared to "up its game" and improve its processes.
The school had been a strident critic of National Standards, which apply to primary schools.
"It feels like we're being bullied, absolutely," Ms Milne-Ihimaera said.
The school has now included National Standards in its charter.