Invest In Super or Pay Off Mortgage?

Should I be putting extra money into super, or paying down the mortgage faster? The Answer Depends on Which Sport You're Playing

There is a question I get asked more than almost any other. Should I put extra money into super, or pay down the mortgage faster?

People ask it expecting a formula. Something clean and mathematical. Compare the interest rate with the investment return, pick the bigger number, get on with your life.

The problem is that formula assumes everyone is playing the same game. They are not. And the consequences of giving the wrong person the right answer for someone else can follow them for decades.

A 35 year old on a strong income with young children and $120,000 in super is not playing the same game as a 57 year old with $180,000 left on their mortgage and retirement three years away. The rules are different. The clock is different. What winning looks like is completely different. Giving them the same answer would be like coaching a marathon runner and a rugby prop with the same training program.

So before I can tell you "do super" or "pay the mortgage," I need to understand which sport you are actually in.

Two People. Same Numbers. Completely Different Game.

Here is what I mean.

Imagine two people. Both are 48 years old. Both earn $120,000 a year. Both have a mortgage at 6.3%. On paper they look identical.

The first has $95,000 in super and needs roughly $800,000 to retire with any comfort. She is behind. Significantly. Every year she does not close that gap, the compounding she is missing is working against her silently.

The second has $580,000 in super already. He is ahead of pace. He has different problems, different options, different risks.

Give them the same advice and you have helped one of them. Maybe.

The spreadsheet does not know which one you are. Only you know that. And most people have never actually checked.

The Variables That Actually Shape Your Decision About Superannuation and Mortgage

The variables that shape this decision interact in ways that are not always obvious. Change any one of them and the answer shifts.

1. Your age and how far you are from preservation age

The younger you are, the more time compound growth has to work inside super before you can access it. An extra $20,000 in super at 35 has more than 25 years to grow before preservation age. The same $20,000 at 57 has roughly three. Early in a game you play to build momentum. Late in the game you protect the lead. The clock shapes everything.

2. Your marginal tax rate — often more decisive than your mortgage rate

Concessional super contributions are taxed at just 15%. If you are earning above $135,000, your marginal rate is 39% or higher. On a $10,000 contribution, that gap is a $2,400 guaranteed saving before the investment does anything at all. For high income earners, the tax argument for super often settles the question before the investment return comparison even begins.

3. Your mortgage offset account — the option most people forget

Money sitting in an offset account earns you your full mortgage rate, tax free, with complete liquidity. At current rates that is often 6% or more on what is effectively a cash account you can access whenever you need it. For many people the right first move is neither extra super nor extra mortgage repayments. It is building the offset buffer first. The question assumes a binary choice that does not have to exist.

4. Your job security and cash flow

Super is locked away. If you maximise salary sacrifice and then face a period of reduced income, that money is unavailable to cover repayments. A mortgage with a redraw facility gives you access when you need it. A family with variable income or a single earner supporting children is carrying real risk on the income side. Reducing financial flexibility to optimise a spreadsheet is not optimising. It is just moving the risk somewhere less visible.

5. Your household structure

Couples have spousal contribution strategies available that can shift super balances, reduce total household tax, and improve retirement outcomes in ways a single person simply does not have access to. The household is the unit of analysis. Looking at one person in isolation and prescribing a strategy for the family is like designing a team game plan by interviewing one player.

None of these variables exist in isolation. They interact. Change one and the answer to all the others shifts.

A 45 year old with a stable government job, a fully funded offset account, and $450,000 in super should be thinking very differently from a 45 year old freelancer with a volatile income, no offset account, and $180,000 in super. The age is identical. The game is completely different.

This is the thing about personal finance that gets lost when it becomes content. The general principles are useful. The specific application is what actually matters.

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The One Thing That Applies to Everyone

There is one thing I will say to every person reading this without qualification.

Make sure you are capturing every dollar of your employer super contribution. Whatever your employer offers above the Superannuation Guarantee, take it. All of it.

If your employer matches additional contributions up to 2% and you are not taking it, you are declining a pay rise. On a $100,000 salary that is $2,000 a year. Not a return on investment. Not a projection. Money offered to you that you chose not to receive.

People leave this on the table all the time because they are focused on the mortgage and not watching this corner of the field. Start here. Always.

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The Coach Does Not Have a Favourite Play

There is a line from the world of sport that I keep coming back to.

The best coaches do not have a favourite system. They have a clear understanding of the players available, the conditions on the day, and what winning actually requires given those constraints. The playbook follows the situation. Not the other way around.

Financial advice should work the same way.

The people I worry about least are not the ones with the highest incomes or the largest super balances. They are the ones who understand which game they are in, have a clear picture of the scoreboard, and have a strategy that fits their actual circumstances rather than a generic answer that fit someone else's.

Super or mortgage is not a maths problem. It is a self-knowledge problem. The maths is the easy part.