Should You Pay Off Your Mortgage or Boost Your Super?

This question comes up constantly with clients in their 50s, and understandably so.

The kids are largely through school. The income is better than it’s ever been. And for the first time in years, there’s actually surplus cash at the end of the month.

The question is where to put it.

The mortgage-vs-super debate gets oversimplified in both directions. Some advisers give blanket ‘always clear the mortgage first’ advice. Others run the numbers and say ‘always maximise super.’ Both camps are missing the point, because the right answer depends on your specific numbers — and there are five variables that matter enormously.

Variable 1: The Return Comparison

This is where most people start, and it’s a reasonable starting point.

If your mortgage interest rate is 6.5% and your super has been earning 8–9% per year in a growth option, the return maths favours super. You’re earning more inside super than you’re saving in interest.

If your mortgage rate is 6.5% and your super has been averaging 4–5% in a conservative option, the maths flips.

The complication: super returns are variable. Mortgage interest savings are guaranteed. There’s a certainty premium to debt repayment that pure return comparisons don’t capture. A guaranteed 6.5% saving is worth more than a projected 6.5% return that may or may not materialise.

Variable 2: Tax — and Why It Usually Tips the Scales

Here’s where super has a significant structural advantage that most people underestimate.

Concessional (before-tax) super contributions — including salary sacrifice — are taxed at 15% inside the fund. If you’re earning $150,000, your marginal rate is 37% plus the 2% Medicare levy. Salary sacrificing $10,000 into super saves you $3,900 in income tax immediately — before the money has earned a single dollar.

That’s a guaranteed, instant return compared to making extra mortgage repayments with already-taxed dollars.

For most Australians earning above $90,000, the tax maths strongly favours maximising concessional contributions before extra mortgage repayments. The tax saving alone often exceeds the mortgage interest saving.

The concessional contribution cap for 2025–26 is $30,000 per year, including your employer’s compulsory contributions (currently 11.5%). If your employer is contributing $17,250 on a $150,000 salary, you have $12,750 of cap remaining — available via salary sacrifice.

Variable 3: Access — The One People Forget

Extra mortgage repayments generally give you access to a redraw facility. The money is locked away in the loan, but accessible if you genuinely need it.

Super is locked away until you reach your preservation age — currently 60 for most people — and even then, only if you’ve met a condition of release.

If you’re 52 with an uncertain employment outlook — perhaps in a volatile industry, a senior role with redundancy risk, or managing a health issue — locking extra cash into super means it’s inaccessible for potentially eight years. That’s not a trivial consideration.

A solid financial position requires liquidity as well as growth. Aggressive super contributions while holding minimal accessible savings is a fragile strategy.

Variable 4: Your Mortgage Payoff Timeline

This one is simple but often ignored. Do the numbers on whether your mortgage will actually be cleared by retirement at your current repayment rate.

If you’re 55 with a $450,000 mortgage on minimum repayments, retiring at 65 — you probably won’t get there. You need a deliberate strategy.

A mortgage in retirement means your income target has to cover debt repayments — which is a drain on an already stretched equation.

Conversely, if you’re 55 with $80,000 left on a 3-year payoff trajectory, the mortgage largely solves itself and your surplus is better deployed elsewhere.

Work out the actual number. Don’t assume.

Variable 5: The Income Question Behind the Decision

Here’s the framing I come back to with clients — and it’s almost never asked in the standard mortgage-vs-super discussion.

Both decisions are about building retirement security. But which one actually produces better retirement income?

A paid-off home reduces your expenses in retirement. It’s not income, but it meaningfully reduces the income you need. If your mortgage is costing you $36,000 a year and you retire mortgage-free, your income target drops by $36,000.

A larger super balance can generate income — through dividends, distributions, and carefully managed drawdowns — but only if it’s structured to do so.

This is the connection to the 2 Cows Strategy. Paying off the mortgage reduces the income you need. Building a dairy cow super portfolio increases the income you have. Done right, both work simultaneously.

 “The 2 Cows Strategy: How to Build Retirement Income That Lasts”

What the Maths Actually Looks Like

Scenario: Both aged 55, $200,000 remaining on mortgage, $400,000 combined super, $10,000 surplus per year to allocate.

Option A — All into mortgage: Mortgage paid off in roughly 10 years by retirement. Super grows from compulsory contributions only.

Option B — All into super (salary sacrifice): Super grows faster due to tax savings. Mortgage remains at retirement but may be manageable with a smaller drawdown from super.

Option C — Split: $5,000 extra repayments per year, $5,000 salary sacrifice. Mortgage largely cleared by retirement, super meaningfully boosted with tax savings along the way.

For most clients in their mid-50s, Option C is closest to the right answer. Not an either/or — a parallel strategy, adjusted for your specific numbers.

How to Get Back on Track

Run through these in order:

1. Are you on track to clear the mortgage by retirement at your current rate? If not, this needs to be solved first.
2. Are you hitting your concessional super contribution cap? If not and you’re above $90,000, you’re leaving a significant tax saving on the table every year.
3. Do you have adequate accessible savings — three to six months of living expenses — before accelerating either strategy? Liquidity first.
4. Run the actual numbers for your situation: your tax rate, your mortgage rate, your balance, your timeline.

The answer is almost always in the specifics. Generic rules get you to the right neighbourhood. Your actual numbers get you home.

Ready to Run Your Numbers?

Stop guessing which strategy is right for your situation. Get the actual maths with a One Page Financial Plan.

For $660 (inc GST), you’ll get:

✓ A clear comparison of mortgage repayment vs super contributions for your income and balance

✓ Tax modelling — how much you’d actually save through salary sacrifice

✓ A realistic payoff timeline and retirement readiness assessment

✓ Specific prioritised recommendations for your situation

✓ 100% satisfaction guaranteed or you don’t pay

One Page Financial Plan

📧 Email: adam@suncow.com.au

📞 Phone: 0418 785 200

About the Author

Adam Carey is a fee-for-service financial planner in Balmain specialising in retirement income planning for Inner West locals aged 50–65.

No commissions. No BS.

He helps pre-retirees figure out if they have enough to retire — often discovering they can stop work sooner than they thought.