Gemma was 52 when she paid off her HECS debt - she wants better for today's students

Ms McWhirter, who lives at Blakehurst and teaches in Sutherland Shire, is appealing for changes to the HECS debt indexation, with more than 27,000 people signing a change.org online petition.

Ms McWhirter said her debt doubled while she spent time out of the workforce raising her family.

"Indexation is currently applied on June 1, just before the ATO applies the annually collected contributions from the PAYE taxation, which would significantly decrease the principal debt," she said.

"In other words, the ATO are holding onto your money - not applying it to your debt, and then indexing you on the maximum amount that they can, while simultaneously holding onto your payments made throughout the year.

"The bare minimum the government needs to do is delay the indexation until after the garnisheed funds for the year have been taken off the principal debt," she said.

"I can't even see how the present system is even legal."

Ms McWhirter said she had been thinking about the "injustice" of it for some time.

"It's not going to benefit me and others who have paid off their debt if the government listens and changes the system, but at least our children won't be burdened as much," she said.

"The way things are they are never going to be able to buy a home because they are living with a $50,000 to $100,000 debt.

"When you think about the pay gap that already exists in the workforce based on gender, it is further evidence of indirect discrimination against women."

Ms McWhirter said she discovered how the debt was indexed by accident, and believes many people don't know how it works.

Last year, due to high inflation, the indexation rate was 7.1 per cent, the biggest increase in 30 years.

With inflation still impacting the economy, HECS debts are likely to be indexed at a high rate once again.

A growing number of federal MPs believe the present system is unfair and are seeking change.

The federal government is considering changes to the HECS repayment system after receiving recommendations from a major review of the university sector.

Additional financial support for low-income students is also a possibility.

Education Minister Jason Clare said the government would respond to the recommendations "in the next couple of months".

It has been reported changes could be announced as early as the budget in May.

HECS allows students to defer paying their portion of the cost until they earn a certain salary, currently $51,550 a year.

Ms McWhirter said, "There wouldn't be a bank in the world that would loan an 18-year-old $50,000".

"But, that's what the government is doing," she said.

"Universities are offering more early entries and students are being enticed into courses without realising the financial ramifications."

Online petition: www.change.org/p/stop-hecs-help-indexation