June 30 marks more than the end of the financial year in Australia—it's the deadline for tax-effective decisions that shape your wealth trajectory for decades. Yet most people file their tax return in October without ever considering whether strategic decisions earlier in the year could have saved thousands in tax and accelerated their path to financial independence.
The gap between someone who "pays their tax" and someone who "optimizes their tax position" compounds year after year. A $5,000 annual tax saving invested at 7% returns becomes $100,000 in additional wealth over 25 years. This guide covers the tax-effective strategies within reach of most Australian workers—and shows you how to model their long-term impact.
Why June Matters: The Time-Sensitive Window
Most tax planning happens after the year ends, during tax return season (July–October). By then, your income is locked in, your spending is finalized, and your investment losses are determined. Too late to change much.
June 30 is different. In the final weeks of the financial year, you can still:
- Make voluntary superannuation contributions (up to caps) and claim the deduction
- Execute salary sacrifice arrangements with your employer for the remainder of the year
- Realize investment losses to offset gains (loss harvesting)
- Accelerate or defer income strategically
- Plan charitable donations before year-end
- Time personal expense deductions carefully
Decisions made in June have immediate tax impact. A $5,000 salary sacrifice contribution in early July is too late; made by June 30, it saves $1,600 in tax (at a 32% marginal rate) immediately.
Strategy 1: Salary Sacrifice—The Biggest Tax Arbitrage
Salary sacrifice is redirecting a portion of your pre-tax income into superannuation. Instead of taking home $100k and contributing to super from post-tax income, you earn $95k in salary and have $5k contributed directly to super. The tax benefit is immediate and powerful.
How It Works
When you sacrifice salary to super, you avoid paying income tax on that amount (FY2026-27: a $180k earner pays 37% + 2% Medicare levy = 39%). Instead, super contributions are taxed at a concessional 15%. Your savings: 39% − 15% = 24% per dollar contributed.
Example: Sarah earns $120,000. Her marginal tax rate (including the 2% Medicare levy) is 32%. She sacrifices $5,000 to super.
- Kept as salary: $5,000 × (1 − 0.32) = $3,400 lands in her pocket
- Sacrificed to super: $5,000 × (1 − 0.15) = $4,250 lands in her super — $850 more working for her straight away
- Grown at 7% for 25 years: the $4,250 becomes ~$23,065 vs ~$18,452 for the $3,400 outside super
- Difference: ~$4,600 extra wealth from a single year's sacrifice — the 17-cents-per-dollar head start compounding
Done consistently, salary sacrifice accelerates super balances materially — the same 15%-vs-marginal-rate gap applies to every dollar, every year.
The Catch: Contribution Caps
Concessional contributions (salary sacrifice plus the 12% employer super guarantee) are capped at $32,500 per financial year (FY2026-27, up from $30,000). Exceed that, and excess contributions are taxed at your marginal rate. Plan carefully if you earn above $180k (employer contributions alone push toward the cap) or already sacrifice aggressively.
Strategy 2: Non-Concessional Contributions—The Post-Tax Route
If you've hit the concessional cap (e.g., you already sacrifice $12k, and your employer adds $20.5k of super guarantee on a high salary—total $32.5k), you can still contribute post-tax money to super. Non-concessional contributions are capped at $130,000 per year (FY2026-27), or up to $390,000 using the 3-year bring-forward rule.
Why? Once in super, earnings are taxed at just 15% instead of your personal marginal rate (up to 47%). Over 20 years on $100k at 7%:
- In super (15% tax on earnings): grows to roughly $340k
- Outside super (39% tax on earnings for a high earner): grows to roughly $250k
- Difference: around $90k extra wealth from concessional super treatment
Non-concessional contributions make sense if you have surplus income above your salary sacrifice cap and want to shelter investments from tax. But timing matters: you must contribute before June 30 to claim the benefit in the current financial year.
Strategy 3: Investment Loss Harvesting
If you hold shares or ETFs outside super, you'll have capital gains each year (dividends, price appreciation). You're taxed on those gains at your marginal rate. But losses can offset those gains.
The Tactic
Before June 30, review your investment portfolio. If you have a holding that's declined in value, selling it realizes the loss. You can then immediately repurchase the same or similar holding (e.g., sell VAS, buy VAS a few days later). You've crystallized the loss without materially changing your portfolio.
Example: You bought $50k of an ASX200 ETF at $75; it's now trading at $68. You have $50k unrealized loss. Sell it, realize the $3,500 loss, then buy it back immediately. That loss offsets capital gains elsewhere in your portfolio, saving tax.
The Catch: Wash Sale Rules
The ATO has rules against "wash sales"—selling and re-buying within a short window to manufacture losses. The specific rule is complex, but safest practice: sell a loss position, wait 30 days, then rebuy. Or buy a different holding (e.g., VAS vs VGS) that tracks a similar market.
Strategy 4: Deductions You Might Have Missed
End of year is when many people realize they've forgotten deductible expenses. The ATO allows deductions for work-related costs:
- Home office: If you work from home, claim a proportion of utilities, rent/mortgage interest, rates, insurance, phone, internet (2024: 67c per hour worked)
- Work-related travel: Mileage, fuel, tolls for car expenses; public transport to clients (commute is not deductible)
- Professional fees: Subscriptions to professional bodies, accreditation costs, ongoing education related to your job
- Work clothing: Only if it's specialized (e.g., safety gear, branded uniform). Regular clothes aren't deductible.
- Equipment: Laptops, phones, furniture purchased for work (>$300 items depreciate; <$300 items are immediately deductible)
- Professional subscriptions: Tax software, industry journals, professional memberships
Keep records: receipts, bank statements, a diary of work-from-home days. The ATO accepts digital copies. One overlooked home office claim can be worth $2,000-5,000 depending on your work setup and marginal tax rate.
Strategy 5: Spousal Super Contributions—Tax Deduction + Offset Income Splitting
If your spouse earns little or no income, you can contribute to their super account and claim a tax deduction (up to $3,000 per financial year). You get the deduction; they build super.
Example: You earn $150k; spouse earns $20k (part-time). You contribute $3,000 to your spouse's super and claim the deduction. You save $3,000 × 39% = $1,170 in tax. Your spouse's super grows tax-advantaged. Decades later, you both have larger super balances and potentially lower tax liabilities in retirement.
The Compounding Impact: Modeling Your Tax Strategy
The power of tax optimization compounds over time. Consider two scenarios:
**Person A: No Tax Planning**
- Earns $120,000 gross
- Takes home $78,000 after tax, super guarantee
- Saves $10,000 post-tax each year (outside super)
- By age 65: $420,000 invested outside super at 7% (after-tax returns)
**Person B: Optimized Tax Strategy**
- Earns $120,000 gross
- Sacrifices $10,000 to super (saves $3,700 in tax)
- Takes home $74,300 but adds back the $3,700 tax savings into investments
- Contributes $10,000 to super, $3,700 to post-tax investments
- By age 65: $520,000 in super (concessional tax treatment) + $245,000 post-tax = $765,000 total
Difference: $345,000 more wealth (45% gain) from tax optimization alone. That's the power of strategic planning compounded over 30 years.
Practical Checklist: June 30 Action Items
- ✓ Check your salary sacrifice setup with HR. Is it optimal given your income and super balance?
- ✓ Review your investment portfolio for loss harvesting opportunities
- ✓ Gather receipts and invoices for work-related deductions (home office, equipment, fees)
- ✓ If you have investment income, consider realizing losses to offset gains
- ✓ If your spouse earns <$54k, consider a $3,000 spousal super contribution before June 30
- ✓ Check your superannuation balance. Are you on track for your retirement goals? (Use FIRE calculator)
- ✓ Set up recurring salary sacrifice for next financial year if you've benefited this year
- ✓ Consult a tax accountant if you have complex income (side hustles, rental property, share investments)
Tax Planning ≠ Tax Avoidance
There's a distinction worth emphasizing. Tax planning uses the tax law as designed (salary sacrifice, super caps, deductions). Tax avoidance exploits gray areas or breaks the law. Everything in this guide is within the ATO's intent and rules.