Today is the last day of the 2025 financial year. You may be thinking about ways to reduce your tax bill, including whether or not to make a concessional superannuation contribution. 

Should you do this, and is it too late? Read on.

Why make a voluntary superannuation contribution?

Australian taxpayers may make a concessional contribution to their superannuation fund. This is a tax deduction on an individual's personal tax return. It is taxed at 15% in the superannuation fund. 

This action can reduce your tax bill while boosting retirement savings. 

However, there is a limit on the amount that can be contributed each financial year. 

For FY25, a maximum of $30,000 can be contributed to super. This includes both employer contributions and voluntary contributions. Employers must pay 11.5% of your pay into your super. You can contribute the gap between this amount and $30,000. 

For example, say you make $100,000 a year. Your employer has paid $11,500 throughout the year into your nominated fund. This means you can contribute up to $18,500 in FY25. 

You can also carry forward any unused contributions for the past 5 years. 

This is particularly advantageous if you've had a large capital gain this financial year. 

With many S&P/ASX 200 Index (ASX: XJO) shares and S&P 500 Index (SP: .INX) companies up significantly over the past 5 years, investors may have reduced their position size or sold out completely this financial year. They're likely to have a large tax bill. 

For example, Commonwealth Bank of Australia (ASX: CBA) is up 159% over the past five years. The majority of experts have warned that it is significantly overvalued and have issued sell ratings. So, it's certainly plausible that many investors have cashed out. 

In the US, chipmaker Nvidia Corp (NASDAQ: NVDA) reached a new all-time high last week of $158.71 and is up 1,624% over the past five years. Again, it's plausible that some investors may have cashed out or reduced their position

Before you eventually lodge your tax return, don't forget to lodge a notice of intention to claim.

Is it too late?

That depends. 

For those with industry and retail super funds, you're likely to have missed the cut-off date. If you contribute today, it won't be processed until next financial year. Instead, it will count as a contribution next financial year. 

According to AustralianSuper, Australia's largest superannuation fund, the cut-off date for this financial year was 23 June.

This can be contrasted with regular work-related expenses (e.g., electronics, stationery, etc.) that can be claimed this financial year as long as they are made and paid for by the end of today.

According to The Australian, many people get caught out making last-minute contributions. 

However, those with a self-managed super fund (SMSF) can still make it in time. 

As long as you transfer funds to your SMSF by 30 June, you can claim the deduction this financial year. That applies to 1.2 million Australians with SMSFs.