The Government has targeted overseas borrowers to make sure they comply with repayment requirements.
Inland Revenue tracks overseas-based borrowers and information sharing with Customs tells it when borrowers arrive in the country and the Department of Internal Affairs can flag when borrowers apply for a passport.
The department estimates that these measures have netted it an additional $123 million in repayments from 2010 to June.
Overdue repayments rose by 21 per cent in 2012/13, driven by an increase in defaulting overseas-based borrowers.
A large group of people overseas reached the end of their automatic three-year repayment holiday and did not meet their repayments afterwards.
Student loans can also be written off due to death or bankruptcy.
In the year to June 30, $15 million was written off because of 685 bankruptcies. The average amount written off was $22,000.