Salary sacrifice to super: limits and timing
Salary sacrifice to superannuation is the most tax-efficient way for most Australians to save for retirement. It reduces your assessable income now (saving tax at your marginal rate) and grows in a concessional tax environment (15% on earnings). Understanding the limits and timing rules prevents costly mistakes.
The concessional contribution cap
2025-26 cap: $30,000 per financial year. This cap applies across all concessional contributions:
- Employer’s mandatory super guarantee contributions (11.5%-12% of ordinary time earnings)
- Salary sacrifice contributions from your pre-tax salary
- Personal deductible contributions (claimed on your tax return)
- Concessional contributions made to multiple funds (combined)
Exceeding the cap triggers excess concessional contribution charges: the excess is taxed at your marginal rate plus an interest charge.
The carry-forward rule
Unused concessional cap amounts from previous years can be carried forward and used in a future year, provided your total super balance at the start of the year is under $500,000.
Example: in 2022-23, you contributed only $15,000 against the $27,500 cap. The unused $12,500 is added to subsequent years’ caps.
By 2025-26, your carry-forward capacity could be $80,000+ if you had low contribution years. This is particularly valuable for:
- Income spikes (sale of business, capital gains, bonuses)
- Career breaks (lower contribution years building carry-forward)
- Self-employed individuals with variable income
The “pre-tax vs post-tax” math
Your employer pays $1 of salary:
- Pre-tax path: $1 to super, taxed at 15% = $0.85 invested
- Post-tax path: $1 - $0.39 tax (at 39% marginal incl. Medicare) = $0.61 invested
The super path puts 40% more capital to work. Compounded over 20-30 years, this is a substantial retirement balance difference.
For very high earners above $250k ($45% marginal + Medicare + Division 293):
- Pre-tax: $1 - $0.15 (contribution tax) - $0.15 (Div 293) = $0.70 invested
- Post-tax: $1 - $0.47 = $0.53 invested
Even at top marginal rates with Division 293, pre-tax contribution still puts 32% more capital to work.
The non-concessional (after-tax) contribution
Non-concessional contributions are made from after-tax money. No tax when they enter super, and earnings inside super are still taxed at 15% concessionally.
Caps:
- Annual: $120,000
- Three-year bring-forward: $360,000 (if under age 75 and total balance permits)
Non-concessional contributions don’t reduce your current tax but do provide long-term access to the concessional earnings environment.
Division 293 - the high-earner penalty
If your income + concessional contributions exceed $250,000, an additional 15% tax applies to your concessional contributions. This effectively doubles the contribution tax from 15% to 30%.
Div 293 still makes pre-tax contributions worthwhile (as shown in the math above) but reduces the margin.
Timing considerations
End of financial year: contributions must be received by your super fund by 30 June to count for that year. Don’t leave it to the last week - processing delays can push contributions into the next year.
Unused caps: plan carry-forward strategically. Use carry-forward in years with:
- Large capital gains
- Sale of business
- Redundancy payments
- Significant bonuses
Retirement transition: once you reach preservation age and stop working (or “transition to retirement”), different contribution rules apply. Plan carefully around this.
The self-employed / sole trader advantage
Self-employed individuals can make personal deductible contributions up to the full $30,000 concessional cap. This is genuinely pre-tax money.
For self-employed earners without mandatory super guarantee:
- The full $30k cap is available for personal deductible contributions
- Claimed as a deduction on the tax return
- Reduces current-year assessable income at marginal rate
For self-employed at 37% marginal: $30k contribution saves $11,100 in tax, while still putting $25,500 into super (after 15% contribution tax).
The spouse contribution option
You can make a non-concessional contribution on behalf of a low-income spouse:
- If your spouse earns under $37,000, you receive a tax offset of up to $540 on an $3,000 contribution
- The contribution counts against your spouse’s non-concessional cap
This is a small but genuine benefit for families with income disparity.
Contribution splitting
You can split up to 85% of your concessional contributions with your spouse. The split contribution counts against your concessional cap but transfers to your spouse’s super balance.
Uses:
- Balance out super across a couple
- Access the spouse’s transfer balance cap (important near retirement)
- Income splitting in retirement (more balance in pension phase of lower-income spouse)
The lifecycle strategy
Under 35: contribute modestly or rely on employer guarantee. Focus on deposit and other wealth building.
35-50: accelerate contributions. This is when carry-forward and higher incomes make super contributions most valuable.
50+: use catch-up contributions heavily. Carry-forward from earlier years becomes accessible. Pre-retirement super build is the most tax-efficient wealth creation.
60-65: transition to retirement. Complex rules apply; specific advice recommended.
Where people go wrong
1. Exceeding caps without knowing: multiple employers each contributing at 11.5% can push you over the $30k cap. Check your contribution caps via myGov.
2. Salary sacrifice timing issues: setting up salary sacrifice mid-year leaves the first portion of the year without sacrifice. Start at the beginning of the financial year where possible.
3. Not using carry-forward: many people with low super balances don’t realise they can carry forward unused caps.
4. Contributing in the wrong year: contributions made in late June may not process until July. Plan for a buffer.
5. Excess non-concessional from unintended sources: gifts, inheritance, employer contributions mislabelled, rollovers - some of these can count against non-concessional caps unexpectedly.
The annual check
Every June, review:
- Total concessional contributions year-to-date
- Remaining cap for the year
- Carry-forward available for next year
- Non-concessional cap usage
- Strategic top-up opportunities
Super contribution strategy is often the single biggest tax optimisation available to middle-and-high-income PAYG earners. It is underutilised by many Australians relative to its value.