Indexed, Repaid From Income, and Written Off at Death
A HECS-HELP debt is indexed annually rather than charged interest, repaid compulsorily only when your income exceeds a threshold, and cancelled when you die. Those three features together make it the cheapest debt most households carry, and make voluntary repayment a poor priority against a mortgage or a super contribution.
- The answer: Compulsory repayments are calculated from your repayment income and collected through the tax system only above the threshold.
- The trap: Salary sacrificing does not reduce repayment income — reportable employer superannuation contributions are added back, so the repayment is unchanged.
- The recommendation: Clear non-deductible debt and fill the concessional cap before making voluntary HELP repayments. The debt is cheaper than either.
Where the AI summary above gets this wrong
"You should pay off your HECS debt as fast as possible to avoid the interest."
That's surface-true. Here's what it misses:
- There is no interest, only indexation — The debt is indexed to a measure of price growth rather than charged an interest rate, which over most periods makes it cheaper than any commercial borrowing.
- It is cancelled at death — An outstanding HELP debt does not pass to the estate or to beneficiaries, which is a genuine consideration for someone carrying one into their sixties.
01 How the debt behaves
The balance is indexed once a year to a measure of price growth. There is no interest charge, so in real terms the debt neither grows nor shrinks except through repayments.
Compulsory repayments are calculated from repayment income and collected through the tax system, at a percentage that rises with income and only above a threshold. Below the threshold nothing is repayable, however large the debt.
The debt is cancelled on death and does not become an estate liability. That is unusual among debts and it is the feature that most changes the calculation for someone carrying one late in their working life.
02 Why salary sacrifice does not help
Repayment income adds reportable employer superannuation contributions back to taxable income, so sacrificing salary into super does not reduce the compulsory repayment.
It also adds total net investment losses and reportable fringe benefits, which means a negatively geared property does not reduce it either. The measure is deliberately broad — the mechanics are in the reportable contributions post.
A personal deductible contribution reduces taxable income and is not a reportable employer contribution, so it does reduce repayment income. That is one of the few places the distinction between the two routes has a practical consequence.
Source: ATO — Salary sacrificing super
03 Where a voluntary repayment ranks
Against a mortgage, the mortgage wins. Non-deductible interest at a market rate costs more than indexation at a price growth rate, so the mortgage is the dearer debt — the comparison is in the loan priority post.
Against a concessional super contribution, the contribution usually wins for anyone at a marginal rate above 15%, because the immediate tax saving exceeds the indexation avoided.
The case for repaying voluntarily is mainly about the compulsory repayment itself: clearing the debt frees up the percentage of income currently being collected, which improves cash flow in the years before retirement. That is a real benefit and it is a cash-flow argument rather than an interest one.
Timing a voluntary repayment before the annual indexation date avoids indexation on the amount repaid, which is worth doing if you have decided to repay anyway. It is not a reason to repay, and it is a reason to choose the month.
Shows: the annual compulsory HELP repayment at your income, and how long the debt takes to clear at that rate with indexation applied. Ignores: changes in your income, the progressive repayment rate structure, and any voluntary repayments.
It is cancelled at death, indexed rather than charged interest, and collected only while you are earning. That combination makes it the cheapest debt most people have, and the least urgent thing to clear. The one honest argument for repaying it is the cash flow the compulsory repayment is taking now.
FAQ
How does an outstanding HECS-HELP debt affect my cash flow in the lead-up to retirement?
A percentage of your repayment income is collected through the tax system while your income is above the threshold. Once you retire and your income falls below it, nothing further is repayable and the debt is cancelled at death.
Should I pay off my HELP debt early?
Rarely as a priority. It is indexed rather than charged interest, so it is cheaper than a mortgage, and a concessional super contribution usually beats it for anyone above a 15% marginal rate.
Does salary sacrificing reduce my HELP repayment?
No. Repayment income adds reportable employer superannuation contributions back, so sacrifice does not reduce it. A personal deductible contribution does.
Sources
Regulator references
- ATO — Tax rates: Australian resident · Australian Taxation Office · 2026The resident marginal rate scale by income year, excluding the Medicare levy.Last verified: 2026-09-07
- ATO — Salary sacrificing super · Australian Taxation Office · 2026Salary sacrifice into super: how the arrangement works and how the contribution is taxed.Last verified: 2026-09-07
Calculator unit tests · the assertions this page's worked example is checked against, and their last result
Changelog
- 2026-09-07 — initial publish (new format)
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Jordan Reeves
Founder of Talk Through Wealth. A software engineer for over a decade before turning to retirement planning, Jordan built the projection engine after watching family members get fragmented, country-by-country advice that never reconciled. He writes about retirement the way the engine computes it: month-by-month, lifetime-long, and skeptical of any rule of thumb that hasn't been run through the math.