Thousands of people with student loans are defaulting on payments, a Ministry of Education report shows.
The student loan scheme annual report shows more than $300 million in payments is overdue, a $100 million increase on a year ago.
One in five student loan borrowers have overdue payments, according to the report, leaving the Government to chase hundreds of millions of dollars.
This includes a big rise in the level of payments owed by people living overseas, to $114 million.
Total student loan debt is now $10.2 billion and is expected to grow to $20 billion by 2022.
The National Union of Students' Associations says the Government needs to make it easier to pay back student loans, otherwise the debt will keep rising.
Union co-president Sophia Blair says the Government needs to allow for online payments for those based overseas.
She says it is inevitable that the debt will nearly double over the next 12 years to $20 billion.
Education Minister Anne Tolley says the Government recently introduced the Voluntary Repayment Bonus scheme which allows people to pay off their loans quicker and people are taking advantage of this.
Nearly 40% of students who left tertiary education with a loan did so without achieving a qualification, the report says.