Sallie Mae, the nation’s largest student-loan company, recently notified one million people nationwide that they owe more money on their student loans than previously indicated.

Computer software miscalculations led Sallie Mae to use inaccurate loan repayment schedules, affecting approximately one million of the seven million people who have Sallie Mae loans.

Sallie Mae manages $87 billion in student loans annually. This error applies only to variable-rate loans in active repayment and does not affect fixed-rate loans or students who have not begun repayment.

Most student loans issued are scheduled for repayment in 10 years, and the software error affects loans dating back from the early 1990s. After unknowingly underpaying for almost a decade, loan recipients are now being notified they have to pay back money they were not aware they owed. Some people have underpaid by more than a $100 a month.

Sallie Mae representatives were unavailable for comment, but, in a story in Minneapolis’ Star Tribune, Martha Holler, a spokesperson for Sallie Mae, said the company is taking steps to ease the transition for repayment.

Holler said that no Sallie Mae recipient will end up paying more money overall because of the error. Extra interest due from the underpayments has been credited to the individual accounts.

Sallie Mae is prohibited by law from extending the loan repayment period beyond ten years unless the recipient requests. Holler said Sallie Mae is offering to extend loan periods to those affected who would prefer to keep their payments smaller.

University of Wisconsin personal finance professor Michael Gutter said that there are negative implications arising from Sallie Mae’s error.

“First off, it’s a blow to anyone’s financial plan, especially when you’re trying to balance so many things at once–rent, living expenses, your loan and trying to save for your future–and this may affect whether or not people choose Sallie Mae as their lender in the future,” Gutter said. “Sallie Mae has been the standard for so long, and now there’s a sense of distrust.”

Gutter also said he does not expect to see much of a legal backlash because people would have to spend thousands of dollars on a lawsuit only to possibly see a couple thousand dollars in student loans forgiven.

Steve Van Ess, director of UW’s Student Financial Services office, said he does not anticipate UW and its students will be greatly affected by the Sallie Mae incident.

“This is an isolated incident, and most of [UW’s] students don’t receive loans from Sallie Mae,” Van Ess said. “This isn’t a huge issue for past Madison students because of that, but for those who are affected it’s a big deal when they have to take on more debt than they thought they had. Nationally, a lot of students will be affected, obviously.”

Gutter said one of the worst consequences of Sallie Mae’s error would be a backlash against taking out loans in general.

“I hope this whole situation won’t discourage anyone from borrowing to get an education,” Gutter said.