Every dollar you pay above your minimum repayment lands directly on the principal. And because Australian lenders charge interest on the principal — daily — every dollar of principal you remove is a dollar that never accrues interest again. That compounds.
How extra repayments save you money
Your scheduled repayment is split into two parts each month: an interest portion (the cost of borrowing) and a principal portion (the actual loan paydown). Early in the loan, most of the payment is interest. Late in the loan, most of it is principal. That's the standard amortisation curve every lender uses.
When you pay extra, the entire extra amount lands on the principal — so the next month's interest charge is calculated on a slightly smaller balance. That saving compounds, month after month, for the rest of the loan's life.
The result is non-linear. An extra $100/month doesn't just save you $100 × 360 months = $36,000. It saves substantially more — typically 1.5–2× that figure on a 30-year loan — because of the compounding effect on the interest base.
Worked example: $600,000 loan at 6.0% over 30 years
Baseline monthly repayment: ~$3,597. Total interest over 30 years: ~$695,000.
| Extra repayment | Total interest saved | Years saved off the term |
|---|---|---|
| $50/week | ~$135,000 | ~6.5 years |
| $100/week | ~$220,000 | ~10 years |
| $200/month | ~$130,000 | ~6 years |
| $500/month | ~$240,000 | ~12 years |
| $10,000 lump sum (year 1) | ~$33,000 | ~9 months |
| $50,000 lump sum (year 1) | ~$160,000 | ~4 years |
The numbers move with the rate. At 7.0% p.a. the savings are larger; at 5.0% they're smaller. The relationship is roughly proportional to the rate.
When extra repayments beat offset
Mathematically the two are equivalent — interest savings are identical dollar-for-dollar. The choice comes down to behaviour and structure.
Use extra repayments when:
- The cash will tempt you if it's accessible. Locking it into the loan removes the option.
- You're on a no-frills variable rate without an offset facility.
- You want a clean, single-account view of "how far ahead" you are.
Use offset when:
- You're on an investment loan. Redraw for personal use breaks deductibility — offset doesn't.
- You want the cash available for emergencies or opportunities.
- Your offset is fee-free or your average balance is high enough that the offset benefit exceeds the package fee.
For most owner-occupiers with discipline and a reasonable cash buffer, offset wins. For everyone else, extra repayments are the simpler answer.
Watch the fixed-rate trap
Fixed-rate loans almost universally cap extra repayments at a few thousand dollars per fixed period — common limits are $10,000 or $30,000 over a 3-year fix. Going over the cap usually triggers a break cost calculated on the difference between your fixed rate and the lender's current wholesale rate, multiplied by the remaining fixed term.
If you have a windfall during a fixed period (a bonus, a tax refund, an inheritance), three sensible options:
- Park it in offset — if your fixed loan permits offset (rare). The benefit applies on the offset portion only.
- Park it in a high-interest savings account until the fixed period ends, then dump it on the loan as a lump sum.
- Pay it down to the fixed-period cap, no further. Track the cap carefully — most lenders show this in your portal.
If you expect to make significant extra repayments, splitting the loan (part fixed, part variable) is the cleanest structure. The variable portion takes the extras with no penalty; the fixed portion gives you rate certainty on the rest. See the Split Loan Calculator to model the split.
The single biggest lever: timing
Extra repayments early in the loan are far more powerful than the same dollar later. A $20,000 lump sum applied in year 1 of a 30-year loan saves more total interest than a $20,000 lump sum applied in year 15 — by a factor of roughly 2×.
The reason is compounding. Money removed in year 1 avoids interest on that $20,000 for 29 more years. Money removed in year 15 only avoids 15 years of interest. Same dollars, very different lifetime impact.
If you're going to make extra repayments at all, front-load them. The first 5–10 years matter the most.
How to set extra repayments up
- Variable loans: Just transfer above the minimum into the loan account. Most lenders show the new term or "months ahead" in the portal automatically.
- Fixed loans: Check the per-period cap before sending anything. Going over usually triggers break costs.
- Direct debit: Increase your scheduled direct debit by the extra amount — this is the simplest set-and-forget approach.
- Round up: Some lenders offer round-up repayments (every transaction rounds up to the nearest dollar; the difference goes onto the loan). Small per-transaction, but consistent.
Run different extra-repayment scenarios in the calculator above. Compare the result against an equivalent offset balance using the Offset Account Calculator.
Frequently asked questions
How much do extra repayments actually save?
On a $600,000 loan at 6.0% over 30 years, an extra $200/month saves around $130,000 in interest and clears the loan roughly 6 years earlier. An extra $50/week (~$217/month) saves around $135,000 and shortens the term by ~6.5 years. The exact saving scales with your rate, balance, and how early in the loan you start.
Are extra repayments allowed on a fixed-rate loan?
Most fixed-rate loans cap extra repayments at $10,000–$30,000 per fixed period. Going over the cap usually triggers a break cost. If you're on fixed and want to make significant extra repayments, either wait for the fixed period to end, or split the loan so part is variable and free for extras.
Should I make extra repayments or use offset?
Mathematically identical — every dollar in offset and every dollar of extra repayment reduces interest by the same amount. The difference is liquidity. Offset stays accessible; extra repayments only come back if your lender allows free redraw, and even then redraw can break the tax deductibility of an investment loan. Default to offset unless you specifically want the discipline of locking the money away.
Do extra repayments reduce my monthly repayment?
Not by default. Most Australian lenders keep your scheduled repayment the same and instead shorten the loan term. If you'd rather lower the monthly outflow than finish early, you can usually request the lender to recalculate (sometimes called 'recasting') after a large lump sum — but the headline interest saving comes from keeping the repayment up.
How early in the loan should I start?
As early as possible. Interest compounds, so a dollar of extra repayment in year 1 saves far more than the same dollar in year 25. The first 5–10 years are where the structure of the loan is most interest-heavy — anything you remove there has the biggest payoff. If cashflow is tight, even $20–$50 a week early on is significantly more powerful than larger payments later.
Can extra repayments be redrawn later?
Most variable-rate loans offer redraw — money paid above the minimum sits in a redraw facility and can be pulled back. Some lenders charge per redraw or set minimum amounts (e.g., $500). For investment loans, redrawing money for a personal purpose (e.g., a car) breaks the tax-deductibility on that portion. Investors should usually use offset instead.
Do I need to tell my lender I'm paying extra?
No, just transfer the money to the loan account. Australian lenders treat anything above the minimum repayment as either an extra repayment (variable loans) or a prepayment counting toward the fixed-period cap (fixed loans). Check your loan portal — it should show the available redraw balance or 'ahead by X months' indicator.
What if I can only make one-off extra payments?
Lump sums work too — typically a tax refund, bonus, or inheritance. A $10,000 lump sum applied to a $600,000 loan in year 1 saves around $33,000 in interest and shortens the term by ~9 months. The earlier in the loan, the bigger the gain. Use the lump sum repayment calculator for one-off scenarios.
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Last updated: 30 April 2026