For twenty years, HECS repayments worked like nothing else in the tax system: crossing a repayment threshold by one dollar triggered a percentage of your entire income. That cliff system is gone. From 1 July 2025, HELP repayments are marginal — you repay a percentage only of the income above the threshold, the same way income tax brackets work.
The mechanics now, in one line: you repay 15c of every dollar of repayment income above $67,000.
What that looks like at real salaries
| Repayment income | Annual repayment | Effective % of income |
|---|---|---|
| $67,000 or less | $0 | 0% |
| $75,000 | $1,200 | 1.6% |
| $90,000 | $3,450 | 3.8% |
| $110,000 | $6,450 | 5.9% |
| $140,000 | $10,950 | 7.8% |
Two things stand out. First, there is no longer any cliff: earning $68,000 instead of $66,000 costs you $150 in HELP, not thousands. Second, repayments scale up fast — the marginal cost of each extra dollar for a graduate above the threshold is their tax rate plus 15%. At $90,000 that's 30% tax + 2% Medicare + 15% HELP = 47 cents in the dollar, which is worth knowing before you price overtime or a side contract.
Note "repayment income" is broader than taxable income — it adds back reportable super contributions, net investment losses and reportable fringe benefits. Salary sacrificing does not reduce your HELP repayment the way it reduces your tax.
Indexation: the part that does the damage
Your HELP balance carries no interest, but every 1 June it is indexed — increased in line with inflation (specifically, the better of CPI or the wage price index since the 2023–24 changes, applied retrospectively). Indexation compounds: a $30,000 debt indexed at 4% grows by $1,200 in a year, which can swallow a large share of that year's compulsory repayments.
This creates the treadmill effect graduates notice: you repay $3,450 through payroll during the year, indexation adds $1,200 back, and the balance falls by barely $2,000. Early on — when the balance is large relative to your repayments — most of your repayment is effectively cancelled by indexation. The HECS payoff calculator models this year by year; a $30,000 debt at a steady $90,000 salary clears in roughly a decade under current settings.
The timing quirk everyone should know
Compulsory repayments are withheld from your pay all year, but they are only applied to your balance after you lodge your tax return — while indexation hits on 1 June based on the balance at that date. Money withheld from July to May sits with the ATO doing nothing while your full balance gets indexed. Consequence: if you plan to make a voluntary repayment, doing it before 1 June reduces the balance before indexation applies. The same $1,000 pays down more debt on 25 May than on 5 June.
Should you pay it off early?
The honest answer for most people is no, not aggressively — with specific exceptions.
HELP is the cheapest debt you will ever hold: it costs inflation, roughly speaking, which means its real cost is near zero. Extra dollars usually earn more in your offset account (6%+ effective, tax-free), in super (concessionally taxed), or even in an ordinary savings account, than they save cancelling indexation. Ranked by after-tax return, voluntary HELP repayments generally come last.
The exceptions are real, though:
- You're near the finish line. If your balance will die within a year or two anyway, killing it early ends the payroll withholding immediately — a 3–8% boost to take-home pay that you can redirect.
- You're about to apply for a mortgage. Lenders assess HELP by its repayment percentage against your income, not its balance. Clearing the debt can lift your borrowing capacity meaningfully — sometimes by more than the debt itself. If a broker tells you the HELP repayment is what's capping your loan, a payout just before application can make sense.
- A large indexation year is looming. When CPI spikes (as in 2023's 7.1%), a pre-June voluntary payment has an unusually high effective return.
Overseas? You still owe it
Since 2017, Australians abroad with HELP debts must file an overseas travel notification and repay based on worldwide income against the same thresholds. The debt is also still indexed every June regardless of where you live. Ignoring it doesn't pause anything — it compounds.
The bottom line
Treat HELP as what it is post-2025: a 15% supplementary marginal tax above $67,000 that ends when the balance dies. Don't fear brackets, don't rush repayment out of debt aversion, do time any voluntary payment before 1 June, and do run the payoff date — and the mortgage scenario — through the calculator before making a five-figure decision on vibes.
Threshold and rate per the marginal repayment system effective 1 July 2025 ($67,000 / 15%; 2026–27 threshold pending ATO indexation). Indexation methodology per the Universities Accord changes. General information, not financial advice.