→Indexation: Eligible accumulated HELP debt is indexed on 1 June using the lower of CPI or WPI. The actual rate changes each year; the calculator uses your assumption for future years.
→Compulsory repayments: Calculated from repayment income, which includes taxable income plus specified add-backs such as reportable fringe benefits, reportable super contributions, net investment losses and exempt foreign employment income.
→Voluntary repayments before 1 June: A payment credited before 1 June reduces the balance indexed that year. Check ATO processing time rather than leaving the transfer until the last day.
Your repayment income is not simply your taxable income. It includes taxable income plus reportable fringe benefits, reportable super contributions, total net investment losses and exempt foreign employment income. PAYG withholding is an estimate during the year; the ATO calculates the final compulsory repayment when assessing your return.
STSL applies marginally, similar to income tax brackets: each threshold below only taxes the slice of income that falls within that band, not your whole repayment income (except at the top tier, where a flat rate applies to the total). These are the current 2026-27 thresholds:
Under the marginal system, your compulsory repayment is the lower of the marginal formula (15c then 17c over the thresholds) or 10% of your total repayment income. The effective rate stays well below 10% until very high incomes.
Repayment income
Compulsory repayment
Effective rate
$60,000
$0
0.0%
$67,000
$0
0.0%
$90,000
$3,071
3.4%
$125,000
$8,321
6.7%
$160,000
$14,176
8.9%
$185,000
$18,426
10.0%
Worked example: on $90,000 of repayment income, the compulsory repayment is 15c on the $20,472 above $69,528 = $3,071 for the year (3.4% effective), withheld through PAYG.
Eligible accumulated HELP debt is indexed on 1 June each year using the lower of the CPI and WPI indexation factors. The 2026 factor was 1.028, an effective increase of 2.8%. Indexation generally applies only to debt that has remained unpaid for more than 11 months. A voluntary payment must be credited before 1 June to reduce the balance indexed that year.
What are the compulsory HELP repayment rates?
From 1 July 2026 (the 2026-27 income year) HELP uses the marginal system introduced in 2025-26. No compulsory repayment applies on repayment income up to $69,528. Above that you repay 15 cents per dollar between $69,528 and $129,717, then $9,028 plus 17 cents per dollar between $129,717 and $186,050, and once your income exceeds $186,050 the repayment is simply 10% of your total repayment income. The marginal rates apply only to income above each threshold — earning exactly $69,528 means no repayment at all.
Should I make voluntary repayments before the indexation date?
Yes, voluntary repayments are most effective when made before the 1 June indexation date. Payments made before indexation reduce the balance that gets indexed, saving you more over time. After indexation, the higher balance generates more interest-like growth, so early voluntary payments have a compounding benefit. This calculator models the effect of timing your voluntary payments.
Tax Accuracy & Sources
Reviewed: March 2026 · Tax year: 2026-27
This calculator is an estimate tool and may not cover all personal circumstances. For state-based taxes, confirm details with your state or territory revenue office.