Extra Super vs Paying Off HECS Faster — Which Should You Prioritise?

The Core Question

Both options use your surplus income productively, but they serve different financial goals:

• Voluntary super contributions: Salary sacrifice or personal deductible contributions are taxed at just 15% inside super (vs your marginal rate of up to 45%). Super then grows with compound returns over decades. The trade-off: the money is locked until preservation age (currently 60).
• Voluntary HECS repayments: Extra payments reduce your outstanding HECS-HELP balance, eliminating future indexation on that portion and bringing you closer to a $0 balance. Once the debt is cleared, your compulsory repayments stop, increasing your take-home pay. The “return” on voluntary HECS repayments equals the indexation rate avoided (typically 3–4% under the CPI/WPI cap).

The fundamental comparison: super offers a larger tax benefit and higher expected returns but locks your money away. HECS repayment offers a modest guaranteed return (avoiding indexation) and frees up future cash flow once the debt is cleared.

HECS Indexation vs Super Returns

Understanding the “cost” of HECS and the “return” of super is essential to this comparison.

HECS-HELP Indexation

HECS-HELP debt is indexed on 1 June each year to the lower of the Consumer Price Index (CPI) or the Wage Price Index (WPI). This cap was introduced by the government in 2023 following the indexation shock of 7.1% in June 2023 (when the cap was applied retrospectively).

Under normal conditions, the indexation rate typically falls between 3% and 4% per year. This means your HECS debt grows by 3–4% annually on the balance as at 1 June — but it does not compound monthly like a mortgage. It is applied as a single annual adjustment.

Crucially, HECS is an interest-free loan — indexation maintains the real value of the debt but does not add a profit margin. There is no benefit to paying it off early beyond avoiding the indexation amount.

Super Fund Returns

According to APRA data, the median Australian super fund has returned approximately 7–8% per year (before fees) over rolling 10-year periods. After fees (typically 0.5–1.0%) and the 15% earnings tax inside super, the net return is closer to 5.5–6.5% for a growth or balanced option.

This comfortably exceeds the 3–4% HECS indexation rate in most years. However, super returns are not guaranteed — in any given year, returns could be negative. HECS indexation, by contrast, is a known cost that you can eliminate with certainty by making voluntary repayments.

When Extra Super Wins

• Young with a long time to retirement (25+ years): More time means more compounding. A $200/month contribution starting at age 25 could grow to over $200,000 by age 60 at 7% gross returns, compared to saving roughly $30,000–$40,000 in avoided HECS indexation.
• Higher marginal tax rate (30%+): The tax saving of 15–30 cents per dollar contributed to super significantly outweighs the 3–4% indexation saving on HECS.
• Small HECS balance relative to income: If your HECS is under $20,000 and your compulsory repayments will clear it within 3–5 years anyway, the indexation cost is minimal and super contributions provide far more long-term value.
• Unused concessional cap space: If you have carry-forward cap amounts from previous years (available when total super is under $500,000), the tax benefit is especially compelling.

When Paying HECS Faster Wins

• Large HECS balance ($50,000+): A $60,000 HECS debt indexed at 4% costs $2,400 per year in indexation alone. Reducing the balance by $10,000 saves $400/year in indexation — a guaranteed, risk-free return.
• High indexation environment: If CPI or WPI is running above 4%, the guaranteed return from avoiding indexation becomes more attractive relative to the uncertainty of super returns.
• Close to paying off HECS: If you owe $5,000–$15,000 and a lump-sum payment would clear the debt entirely, eliminating the compulsory repayment from your payslip immediately boosts your take-home pay by 1–4% of gross income (depending on the repayment rate at your income level).
• About to cross a repayment threshold: If your income is close to a higher HECS repayment band, paying down the debt before 1 June can reduce the indexation amount applied that year.
• Low marginal tax rate (16–19% bracket): The super tax saving is only 1–4 cents per dollar, which barely justifies locking money away when you could eliminate a debt that costs 3–4% per year.

The Maths — $200/Month Over 10 Years

The table below models directing $200 per month ($2,400/year) to either extra super contributions (via salary sacrifice) or voluntary HECS repayments, for a worker in the 30% tax bracket.

At the 30% tax bracket, the outcomes are remarkably close over 10 years. The key differentiator is accessibility: the HECS reduction immediately benefits your cash flow once the debt is cleared, while the super balance remains locked. At higher tax brackets (37% or 45%), the super option pulls ahead more decisively due to the larger tax saving.

Frequently Asked Questions