Whether you are looking to claim a deduction in your business or as an individual it is important to understand how the tax system works.

A tax deduction often feels like “free money,” but in reality it just reduces your taxable income — so the tax benefit is only a fraction of what you spend. Here’s a clear way to think about it:

What a Tax Deduction Actually Does

A tax deduction reduces the income the government taxes.

• Without a deduction:
   You pay tax on your full income.
• With a deduction:
  You pay tax on a lower amount of income.

It does not give you back the full amount you spent.

Simple Example

Let’s say:

• Your income: $100,000
• Tax rate: 30%
• You claim a $10,000 deduction

Without deduction

• Taxable income = $100,000
• Tax = 30% of $100,000 = $30,000

With deduction

• Taxable income = $90,000
• Tax = 30% of $90,000 = $27,000

Result

• Tax saved = $3,000
• But you spent = $10,000

You are still $7,000 worse off in cash terms

The Core Principle

A deduction only saves you:

Your tax rate × the amount deducted

So:

• If your tax rate is 30% → you “get back” 30 cents per dollar spent
• If your tax rate is 45% → you get back 45 cents per dollar

You always spend more than you save.

Why You Usually Have to Spend Money

Most deductions exist because you incurred a cost related to:

• Earning income (e.g. work expenses)
• Running a business
• Investing (sometimes)

So to claim the deduction, you generally:

1. Spend money
2. Then reduce your taxable income by that amount

Real-World Examples

1. Work expenses

• You buy tools or training: $1,000
• Tax saved (30%): $300
• Net cost: $700

2. Business expenses

• Marketing spend: $20,000
• Tax saved (30%): $6,000
• Net cost: $14,000

The Key Insight (Very Important)

A deduction should never be the reason you spend money

Bad thinking:

“I’ll buy this because it’s tax deductible”

Better thinking:

“If I need to spend this anyway, the deduction softens the cost”

When Deductions Do Make Sense

They’re valuable when:

• The expense generates income (e.g. business investment)
• You needed it anyway
• It improves long-term financial outcomes (education, tools, etc.)

Deduction vs Tax Credit (Quick Contrast)

This helps clarify why deductions are limited:

• Deduction: reduces income → partial benefit
• Tax credit: directly reduces tax → full benefit

Example:

• $1,000 deduction → saves ~$300 (at 30%)
• $1,000 credit → saves $1,000

Bottom Line

• You almost always spend $1 to save less than $1
• The actual benefit = your marginal tax rate times the expense
• Deductions reduce pain, they don’t create profit

McNamara & Company - Chartered Accountants, located minutes from the Melbourne CBD
www.mcnamaraandco.au/contact-us
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Email admin@mcnamaraandco.au
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