Excess contributions tax: when you've put too much into super — and how to fix it

Australia's superannuation system is built around contribution caps. Exceed those caps, and the excess contributions tax applies — and for non-concessional excess under the default treatment, the effective rate is 47%. The system is strict on purpose: the concessions available inside super (low tax on earnings, tax-free pension phase) are calibrated to defined contribution limits, not unlimited accumulation. But mistakes happen, and when they do, the consequences are manageable if addressed promptly. The worse outcome is ignoring an ATO determination and allowing the default treatment to apply when a release election would have been far cheaper.

What are the contribution caps?

Two caps govern how much can go into super in a given year. The concessional contributions cap — covering employer Superannuation Guarantee payments, salary sacrifice, and personal deductible contributions — is $30,000 per year (FY2025-26). Where a member's Total Super Balance (TSB) was below $500,000 at the prior 30 June, unused cap space from the previous five years can be carried forward and added to this year's cap, allowing catch-up contributions above $30,000.

The non-concessional contributions cap — personal after-tax contributions — is $120,000 per year (FY2025-26). Members below age 75 whose TSB was below $360,000 at the prior 30 June can bring forward up to three years of NCC cap space, allowing up to $360,000 in a single year. The NCC cap is also subject to a TSB ceiling: once a member's TSB reaches or exceeds the general Transfer Balance Cap ($2.0 million for FY2025-26), the NCC cap drops to zero — no after-tax contributions at all.

What happens when you exceed the concessional cap?

If total concessional contributions in a year exceed the $30,000 cap, the excess is included in the member's personal assessable income and taxed at their marginal rate. A 15% tax offset applies, reflecting the contributions tax already paid inside the fund on that amount. In addition, an excess contributions charge (essentially an interest penalty) applies for the time between when the contributions were made and when the assessment is issued. For members on the top marginal rate (45% plus 2% Medicare = 47%), the net effective tax burden on excess CCs is substantial.

The ATO allows a release election: the member can elect to have up to the amount of excess released from super (plus 85% of associated earnings on that amount) to pay the tax bill. This is generally the preferred path — it allows the tax to be funded from within super rather than from personal cash flow, and avoids the compounding effect of the excess remaining inside the fund generating further issues.

What happens when you exceed the NCC cap?

Excess non-concessional contributions under the default treatment are taxed at 47% — the top marginal rate plus Medicare levy, applied to the excess amount. This is the most punitive outcome in the contributions framework and applies to after-tax money the member has already paid income tax on. A member who accidentally puts $20,000 too much into super as non-concessional and takes no action faces a $9,400 tax bill on top of what they've already paid.

The release election is essential for excess NCCs. Electing to release the excess (plus 85% of associated earnings) results in the amount being removed from the fund, with the earnings component taxed at marginal rates with an offset for the 15% already paid inside the fund. The excess NCC itself is released tax-free, since it was after-tax money to begin with. The outcome is far better than the 47% default, and for most members there is no rational reason to decline the election.

What does a cap breach look like in practice?

A common cause of concessional cap breach is the combination of employer SG and salary sacrifice in a year of high earnings. Consider a member earning $250,000 in FY2025-26. The employer's Superannuation Guarantee obligation is 12% (the SG rate as of 1 July 2025) — meaning $30,000 goes in as compulsory employer contributions before any election. If the same member also directs $5,000 of salary to salary sacrifice, total concessional contributions are $35,000 — $5,000 over the cap. The ATO will identify this and issue a determination. At a 47% marginal rate, the excess is included in income, attracting roughly $2,350 in additional tax (before the 15% offset — net somewhat less). The release election allows the $5,000 plus associated earnings to be released from super to fund the tax payment. The lesson: salary sacrifice amounts need to account for what the employer is already contributing.

How do you find out about an excess and act in time?

The ATO matches contribution data from funds against the cap limits after the financial year. When excess is detected, it issues an excess contributions determination, which sets out the excess amount, the tax consequences, and the election options. Elections typically must be made within 60 days of the determination — this deadline is firm and missing it forfeits the release election option.

Members can monitor their running contribution totals through the year via myGov and the ATO online portal, which aggregates data across all super funds. Proactive mid-year checking allows contribution adjustments (reducing salary sacrifice, deferring a planned NCC) before a cap breach crystallises.

How do you prevent excess contributions?

Most excess contributions are avoidable with straightforward tracking. The three highest-risk scenarios are: multiple funds where contributions are not monitored in aggregate; the SG-plus-salary-sacrifice overlap; and bringing-forward NCC cap space without confirming the TSB test result at the prior 30 June. For members making substantial contributions across multiple mechanisms, an adviser can coordinate the numbers and flag accumulating exposure well before year-end.