The department's director of future directions change projects, Katrina Williams, said in the Official Information Act response, that part of Inland Revenue's standard practice was to generate daily and monthly reports that identified borrowers who had overpaid.
After Inland Revenue is satisfied it has received all employer payment reductions, the loan and account information is correct, repayment obligations have been met and the borrower doesn't intend to start a new loan, a letter is sent to the borrower who must:
* Change their tax code to one that does not include the SL repayment code.
* Tell their employer to stop any extra deductions.
* Cancel any automatic payments set up with a bank to repay a loan.
The president of the Auckland University Students' Association, Arena Williams, said Inland Revenue's system needed to be changed.
"Everyone with a student loan has been through hours of fighting with Studylink while they were at university. There's definitely a perception that Studylink deliberately makes it difficult to manage your student loan," Ms Williams said.
"The same applies for grads and the IRD system."
Ms Williams said graduates should be encouraged to pay back their loans, and thought a big part of the problem of people going overseas and not repaying the loans was that it was difficult to pay them back.
"If people know that they're likely to overpay their loans, they'll be even less inclined to pay their loans back. IRD needs a transparent system that's easy to use."