HECS Debt vs Investing in Australia: Should You Pay It Off or Invest? (2026)

Author: Tepuy Solutions | Date: April 2026
Category: Strategy, Debt, Investing

HECS-HELP debt is widely described as "interest-free" — but that's not quite right. It's indexed annually to CPI, meaning it grows with inflation every June. In years of high inflation (like 2022–23, when CPI hit 7%), HECS balances grew by 7% overnight — faster than many savings accounts were paying. Understanding this distinction is the starting point for deciding whether voluntary HECS repayment or investing makes more sense for you.

How HECS-HELP Actually Works

HECS-HELP debt is repaid through the tax system once your income exceeds the minimum repayment threshold — $69,528 for 2026–27 (it was $67,000 in 2025–26, up from $54,435 in 2024–25). Since 2025–26 the compulsory repayment is calculated on marginal rates: only the income above the threshold is charged, not your whole repayment income. That is a change from the old tiered system, where crossing a threshold applied a percentage to every dollar you earned. These are collected through your tax return or PAYG withholding.

The debt is indexed on 1 June each year to the lower of CPI or the Wage Price Index (WPI). For 2024–25, CPI indexation was approximately 3.2%, meaning a $30,000 HECS balance grew by $960 before any repayments were made. For 2022–23, indexation was 7.1% — a $30,000 debt grew by $2,130 in a single year.

Two things that changed, and one that catches people out

All study and training loan balances were reduced by 20%, effective before 1 June 2025. If you have not looked at your balance since then, the figure you are carrying in your head is too high, and the payback arithmetic below starts from a smaller debt than you may expect.

Salary sacrificing does not reduce your compulsory repayment. Reportable employer superannuation contributions are added back when your repayment income is worked out, so sacrificing into super lowers your taxable income but not the HECS repayment calculated on it. This matters for the comparison in this article: the common move of salary sacrificing instead of making voluntary repayments does not shrink the compulsory amount coming out through the tax system.

The Core Question: Voluntary Repayment vs Investing

Voluntary repayments reduce your HECS balance immediately, saving future indexation. The question is whether the "return" on that early repayment (avoided indexation) beats what you'd earn by investing the same amount.

In normal inflation environments (2–3%), the maths strongly favours investing over voluntary HECS repayment. At CPI of 7%+, the comparison is closer — but even then, high inflation typically means real investment returns are also compressed, so neither option is a clear winner.

The Mortgage Interaction (Important)

HECS debt is included in the lender's serviceability assessment when you apply for a home loan. Your mandatory repayment amount reduces the income available to service a mortgage, lowering your borrowing capacity — typically by $30,000–$60,000 in loan capacity per $10,000 of HECS balance, depending on the lender's assessment rate.

If you're planning to buy property in the next 1–2 years, paying down HECS first can unlock meaningful additional borrowing capacity — which may be worth more than the investment return you'd forgo. This is one case where voluntary HECS repayment genuinely wins on financial grounds.

The Case for Investing Instead

For most graduates who are not immediately buying property, the case for investing over voluntary HECS repayment is strong:

• HECS indexation (2–3% in normal years) < ASX returns (7–10% long-run). The gap is large enough to compensate for risk, especially over 5–10 year horizons.
• HECS gets paid off automatically. Mandatory repayments via PAYG mean the debt eventually disappears regardless. You don't need to rush it.
• Time in the market matters more. Starting a share portfolio at 25 vs 30 creates roughly 60% more compounding by retirement — the delay of investing while paying HECS has a larger long-run cost than the indexation savings.
• HECS debt doesn't compound like other debt. It grows only by CPI each year — it doesn't compound on itself the way a mortgage or credit card does.

The Case for Paying Off HECS

There are genuine situations where voluntary HECS repayment is the right call:

• Property purchase within 2 years. Paying HECS down increases your borrowing capacity, which in a rising market may generate more wealth than the foregone investment return.
• High inflation environments. When CPI indexation exceeds 5–6%, voluntary repayment becomes competitive with after-tax investment returns — especially for conservative investors who don't want market exposure.
• Psychological debt aversion. If carrying HECS debt causes genuine stress and prevents you from making other financial decisions clearly, paying it down may be the right call even if it's not optimal on paper.
• Nearing the end of your balance. If your remaining HECS is small (under $5,000), paying it off in a lump sum removes it from lender assessments and simplifies your tax return — a marginal administrative win worth considering.

Should You Split: Do Both?

One practical approach: invest enough to get compounding started, and let mandatory HECS repayments do their job. Don't make voluntary repayments unless you're buying property soon. This gives you the long-run investment compounding while your HECS gets repaid at a "CPI" cost — the cheapest debt you'll ever have.

2026–27 HECS Repayment Thresholds

• Below $69,528 — no compulsory repayment.
• Above $69,528 — 15c in the dollar, charged only on the income above the threshold.
• Above $129,717 — $9,028 plus 17c for each $1 over $129,717.
• A top band is charged at 10% of your total repayment income rather than marginally. Published sources disagree on where it cuts in, so we are not quoting a figure here — confirm the cut-in against the ATO’s current repayment-rate table before relying on it.

On $80,000, the compulsory repayment is 15c on the $10,472 above the threshold — about $1,571/year, or 2.0% of income, before any voluntary amounts. Under the old tiered system the same income attracted roughly $4,400, so the marginal change cut it by about two thirds. A $30,000 debt would be extinguished in roughly 6–7 years through mandatory repayments alone.

Disclaimer

This article is general information only. None of the figures on this page come from a Tepuy calculator — the repayment thresholds and rates, the worked examples, and the borrowing-capacity estimates alike — no engine in this repository models HECS-HELP, so unlike our stamp duty, LMI or CGT numbers these cannot be checked against code and are prose only. HECS-HELP thresholds, indexation rates, and repayment rates are set annually — verify current figures at studyassist.gov.au. Consider professional financial advice for decisions involving large balances or property purchases.