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Business Loan Interest Tax Deduction in Australia: What You Can Claim in 2026

9 mins read
Picture of Colin Lua
Colin Lua
Portfolio Lead, Accounting & Tax Operations – Australia
Colin Lua is a seasoned accounting professional with over 15 years of experience, including the past two years as Portfolio Lead in Accounting & Tax Operations at Sleek Australia. A trusted expert in SME accounting and taxation, Colin specialises in supporting businesses across retail, investment management, and professional services.

He holds multiple professional accreditations, including being a CPA Australia member, NTAA Fellow, and Registered Tax Agent. His academic credentials include a Bachelor of Business, Master of Accounting, and an Executive MBA—underscoring his strong foundation in business and finance.

At Sleek, Colin works closely with small and medium businesses, helping them navigate financial and tax compliance with confidence and clarity. He finds deep satisfaction in achieving successful outcomes for clients, from accurate bookkeeping to timely tax lodgements—believing that it’s the small victories that make a big impact.

Beyond his professional life, Colin enjoys reading history and business books, and recharging on nature hikes. As a child, he aspired to be a business person—something he now fulfills by supporting others on their entrepreneurial journey.
Business Loan Interest Tax Deduction in Australia: What You Can Claim in 2026
Key takeaways
  • Interest is deductible only if the loan is used to generate business income
    The ATO applies a strict “use of funds” test, the purpose of the loan determines what you can claim.

  • You can’t claim the full loan repayment, only the interest and certain costs
    Principal repayments are not deductible, and mixed-use loans must be carefully apportioned.

  • Recent rule changes make loan structuring more important than ever
    With ATO interest (GIC/SIC) no longer deductible from 1 July 2025, how you manage and refinance debt directly impacts your tax position.

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In this article

Are you paying more tax than you should? Many Australian business owners take out loans to manage cash flow or cover expenses, but misunderstand how deductions actually work, especially when it comes to interest.

The business loan interest tax deduction can reduce your taxable income, but only if it meets ATO requirements. With recent rule changes, knowing what’s deductible (and what’s not) is more important than ever.

Without guidance from a qualified tax accountant, it’s easy to miss legitimate claims or apply the rules incorrectly.

This article breaks down exactly what you can claim under current ATO rules, so you can reduce your tax legally and avoid costly mistakes.

Tip

Structure your loan correctly from the start. Fixing deductibility issues later is difficult and often limits what you can claim.

Is business loan interest tax deductible in Australia?

Yes, business loan interest is generally tax deductible in Australia when the loan is used to produce assessable business income.

Under ATO rules, the focus is on how the borrowed funds are used. If the loan supports your business such as paying suppliers, covering wages, purchasing equipment, or funding working capital, the interest is typically claimable.

To keep it clear:

  • Deductible: Interest on loans used for business income-producing activities
  • Not deductible: Loan principal repayments or interest on private use
  • Mixed use: Only the business portion of the interest can be claimed

Read more: Tax Minimisation Strategies for Small Business Owners in Australia

One important update to be aware of:

From 1 July 2025, interest charged by the ATO (such as General Interest Charge and Shortfall Interest Charge) is no longer tax deductible, even if the underlying debt is business-related.

The rule is simple: interest is deductible only to the extent the borrowed funds are used to generate business income.

Because the ATO applies this strictly, maintaining a clear audit trail and ensuring the loan is used correctly is essential to support your claim.

Stay compliant on interest claims, not caught in errors
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What parts of a business loan are tax deductible (and what isn’t)?

When it comes to a business loan interest tax deduction, the ATO does not allow you to claim your full loan repayments as a deduction. Only certain components of those repayments are deductible.

The key distinction is between interest and principal.

  • Interest is the cost of borrowing and is generally deductible (if the loan is used for business purposes).
  • Principal repayments are simply paying back the original loan amount and are not deductible

What can you claim as a business loan interest tax deduction?

If the loan is used for business purposes, the following are generally deductible:

  • Interest on the loan
    The primary deductible component, as long as the funds are used to produce assessable income.
  • Interest on overdrafts and lines of credit
    Deductible where these facilities are used for business cash flow or operations.
  • Loan establishment fees and borrowing costs
    This includes application fees, legal fees, and lender charges.
    Under ATO rules, these may need to be spread over the loan term (or up to 5 years) rather than claimed upfront, depending on the amount.
  • Ongoing loan account fees
    Such as monthly account-keeping or facility fees charged by the lender.
  • Break costs or early repayment fees
    These may be deductible where they relate to a business loan, particularly if incurred in refinancing.

Read more: Tax Laws Australia 2026: What Businesses Must Know

What is not tax deductible on a business loan?

  • Loan principal repayments
    These are not deductible, as they represent repayment of capital, not an expense.
  • Interest on the private portion of a loan
    If any part of the loan is used for personal purposes, that portion of the interest must be excluded.
  • ATO interest charges (GIC and SIC) from 1 July 2025 onwards
    These are no longer deductible, even where the underlying tax debt relates to business activities.

What requires careful treatment under ATO rules?

Some areas aren’t black and white and need closer attention:

  • Mixed-use loans
    Interest must be apportioned based on actual usage. This requires accurate tracking of how funds are applied.
  • Redraws and refinanced loans
    Each new use of funds is assessed separately. Deductibility depends on the purpose of the redraw or new loan, not the original facility.
  • Capitalised interest
    If interest is added to the loan balance instead of being paid, it may still be deductible but only if it continues to relate to business use and meets ATO criteria.

You’re not claiming the loan, you’re claiming the cost of borrowing, and only to the extent it supports your business income.

Insights

The biggest tax advantage doesn’t come from having a loan, it comes from how the loan is used and documented.

Is interest on a business loan to pay tax debt deductible?

This is where things have changed recently and where many businesses are getting caught out.

From 1 July 2025, the ATO no longer allows a deduction for interest charged on tax debt, including the General Interest Charge (GIC) and Shortfall Interest Charge (SIC). So if you’re on an ATO payment plan, that interest is no longer tax deductible, even if the underlying debt relates to your business.

However, the position is different if you use a business loan to repay that tax debt.

  • If the original tax liability is business-related such as GST, PAYG withholding, or income tax from business activities then taking out a business loan to clear that debt generally maintains the connection to income-producing purposes. 
  • As a result, the interest on that loan is typically deductible under standard ATO rules.

The distinction comes down to what the debt relates to. 

  • If the tax debt is personal, the interest won’t be deductible. 
  • But if it arises from business income, refinancing it through a properly structured business loan can restore deductibility on the interest, something you no longer get with the ATO.

In practical terms, this means, businesses now need to be more deliberate. 

  • Leaving debt with the ATO may be simpler, but it comes with non-deductible interest. 
  • Moving that debt into a business loan can improve your after-tax position, provided it’s structured correctly and supported by clear records.
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How to maximise your business loan interest tax deduction? 

Maximising your business loan interest tax deduction comes down to how well your loan is structured and documented, not just whether you have one.

Here’s what actually makes the difference:

  • Keep the loan purpose clear
    The ATO looks at how the funds are used. If the loan is fully used for business activities, the interest is generally fully deductible. Mixing personal and business use reduces what you can claim.
  • Avoid mixed-use borrowing where possible
    Once a loan is used for both personal and business purposes, you’re required to split (apportion) the interest. This adds complexity and often leads to missed or incorrect claims.
  • Align the loan with the correct business entity
    The borrowing should sit with the entity generating the income (e.g. company, trust, sole trader). Misalignment can weaken the link required for deductibility.
  • Maintain a clear audit trail
    You need to be able to show where the money went. Bank records, invoices, and payment trails help support your claim if reviewed by the ATO.
  • Review how you manage tax debt
    With ATO interest no longer deductible from 1 July 2025, using a business loan to refinance business-related tax debt can improve your after-tax position, if structured correctly.
  • Get advice before you borrow, not after
    The biggest gains come from setting things up correctly upfront. Fixing it later is harder and often limited.

In practice, the deduction itself is straightforward but maximising it depends on getting the structure right from day one.

Common mistakes that can lead to denied interest deductions

Even when the rules are clear, small missteps in how loans are used or reported can lead to denied deductions or ATO penalties.

1. Mixing business and personal use

If a loan is used for both purposes, only the business portion of the interest is deductible. Without accurate records, businesses often overclaim or lose legitimate deductions.

2. Treating the full repayment as deductible

Only the interest (and certain fees) can be claimed, not the principal. This is one of the most common reporting errors.

3. Changing how the loan is used over time

If the purpose of the loan shifts for example, from business use to private use, the deductibility of interest changes as well. Failing to adjust this can lead to incorrect claims.

4. Capitalising interest without understanding the impact

Where interest is added to the loan balance instead of being paid, the timing and treatment of deductions can become more complex and must still meet ATO requirements.

5. Poor or missing documentation

If you can’t clearly show how the borrowed funds were used, the ATO may deny the deduction even if the expense was business-related.

Read more: Taxation Accountant for Small Business in Australia: What They Do & When You Need One

How does business loan interest affect your tax and cash flow?

Understanding the business loan interest tax deduction is important but it’s only one part of the bigger financial picture.

While interest on a business loan can reduce your taxable income, it doesn’t reduce the actual cost of borrowing. It simply lowers the after-tax cost, depending on your applicable tax rate.

For example:

Loan amount

Interest rate

Annual interest

Company tax rate

Estimated tax saving

$100,000

5%

$5,000

25%

$1,250

$100,000

5%

$5,000

30%

$1,500

$250,000

5%

$12,500

25%

$3,125

$250,000

5%

$12,500

30%

$3,750

It’s also important to consider how the loan fits into your broader tax position.

  • If the borrowed funds are used to acquire business assets (like equipment or property), the interest may still be deductible, but the asset itself could trigger capital gains tax (CGT) when sold. 
  • These outcomes should be assessed together, not separately.

For GST, the treatment is often misunderstood. 

  • Loan interest is generally input taxed in Australia, which means GST is typically not applied to interest and you generally can’t claim GST credits on it. 
  • Misreporting this is a common issue flagged during ATO reviews.
Quick note

A loan being “business-related” isn’t enough. If you can’t clearly show how the funds were used, the ATO may deny the deduction.

How can Sleek’s tax accountants help manage business loan interest tax deductions?

Managing the business loan interest tax deduction requires accurate records, correct loan structuring, and a clear understanding of how ATO rules apply to your business. Sleek helps businesses stay on top of their accounting and tax obligations without the administrative burden.

  • End-to-end accounting and tax support: From bookkeeping and BAS lodgements to annual tax returns, we keep your financial records organised and aligned with ATO requirements.
  • Maximising eligible tax deductions: We ensure your loan interest and related expenses are correctly recorded and claimed, helping you capture every deduction you’re entitled to.
  • A dedicated tax accountant: Your accountant helps manage reporting obligations, reviews how your loans are structured, and ensures your tax filings remain accurate and compliant.
  • Transparent, all-inclusive pricing: Clear and predictable pricing with no hidden fees, so you always know exactly what you’re paying for.

Simplify your tax obligations, keep your finances organised, and stay confidently compliant with Australian tax regulations.

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Frequently Asked Questions

What happens if I redraw or reuse funds from an existing business loan?

Redrawing funds can change the deductibility of interest. Each use must be assessed separately if redrawn amounts are used for private purposes, that portion of the interest becomes non-deductible and must be apportioned.

Is interest still deductible if my business is temporarily not generating income?

In many cases, yes as long as there is a clear intention to produce income and the loan remains connected to business activities. However, this can become complex and may require professional assessment.

What level of documentation does the ATO expect for interest deductions?

The ATO expects a clear audit trail linking borrowed funds to business use including loan agreements, bank statements, and evidence of how funds were applied. Poor documentation is a common reason for denied claims.