Key Takeaways
- Interest deductibility on commercial loans is determined by the purpose for which the borrowed funds are used, not by the security supporting the loan or the type of property mortgaged.
- Borrowing to acquire income-producing assets (commercial property leased to tenants, business assets used in trading operations) generally produces deductible interest; borrowing for private or non-income-producing purposes generally does not.
- Mixed purpose loans (where part of the borrowing is for income-producing purposes and part is for private purposes) require interest apportionment and create ongoing record-keeping obligations that can be complex to manage.
- This guide explains only the general principles. Every borrower’s tax position depends on their specific circumstances; personalised tax advice from a qualified accountant or registered tax agent is essential before relying on any deductibility position.
Why This Article Is About Principles, Not Specific Tax Advice
Tax deductibility is one of the most material factors in commercial property and business borrowing decisions. The same loan can be highly tax-efficient or completely non-deductible depending on how the funds are used, the borrower’s entity structure, and the connection between the borrowing and income-producing activities. Borrowers who understand the deductibility position before settlement can structure transactions to optimise the tax outcome; borrowers who only consider it afterward often face missed opportunities or unexpected liabilities.
However, deductibility analysis is fact-specific and depends on individual circumstances. The Australian Taxation Office’s rulings on interest deductibility are technical, with decades of case law shaping how the principles apply in specific situations. This article explains the general principles a tax adviser would apply, but does not provide tax advice for any specific situation. Hence, every borrower should engage a qualified accountant or registered tax agent before relying on any deductibility position. The cost of personalised tax advice is small relative to the tax implications of getting this wrong.
This guide explains the general principles of commercial loan interest deductibility in Australia and the situations where personalised tax advice is essential. For commercial loan structure decisions that affect tax-effective borrowing, speak with a Loanworx broker about commercial loan structure for tax-effective lending alongside your accountant; the broker structures the loan, the accountant confirms the tax treatment, and the two together produce the right outcome for the specific situation.
The Fundamental Principle: Deductibility Follows Purpose
The central principle of interest deductibility in Australia is that interest is deductible to the extent the borrowed funds are used to produce assessable income. This principle has been confirmed through extensive case law and is set out in Australian Taxation Office rulings. The principle is purpose-based: what matters is how the borrowed money is actually used, not what asset the lender holds as security or what the loan is called.
Purpose Versus Security
The same property can secure either deductible or non-deductible borrowing, depending on how the borrowed money is used. A commercial property mortgage securing a loan to acquire investment property produces deductible interest. The same commercial property mortgage securing a loan used to fund a family holiday produces non-deductible interest. The lender treats both loans the same way; the tax outcome differs entirely based on use.
Following the Money
The ATO’s general approach is to trace the borrowed funds to their actual use. If $500,000 is borrowed and used to purchase a tenanted commercial property, the interest on that $500,000 is generally deductible against the rental income. If $200,000 of the same borrowed funds is later redirected to private purposes, the interest on that $200,000 portion typically ceases to be deductible. The connection between borrowing and income-producing use must be maintained for deductibility to continue.
The Income-Producing Test
Interest is deductible when the borrowed funds are used for income-producing purposes: acquiring assets that produce assessable rental income, funding business operations that produce trading income, or financing investments that produce dividends or other investment income. Interest is not deductible when the funds are used for non-income-producing purposes: private property, personal lifestyle, family purposes, or capital purposes that don’t produce ongoing income.
Why Tax Advice Is Essential
The principle sounds straightforward, but applying it to specific situations requires judgement. Questions like ‘when is a business asset producing assessable income?’ or ‘how do you apportion interest on a mixed-purpose loan?’ have technical answers that depend on case law, ATO rulings, and the specific circumstances. A qualified accountant or registered tax agent can apply the principles to a specific situation; this article cannot.
Common Commercial Borrowing Scenarios and Their General Deductibility Position
Several common commercial borrowing scenarios are worth understanding at a principle level, with the strong caveat that every situation requires personalised tax advice.
Purchasing Commercial Property for Investment
Where commercial property is purchased to be leased to tenants producing rental income, the interest on the borrowing is generally treated as deductible against that rental income. This is the most straightforward scenario for deductibility in commercial property. The income-producing purpose is clear (rental income), and the borrowed funds are directly applied to acquiring the income-producing asset. Specific deductibility depends on the entity structure, the lease arrangements, and other circumstances; an accountant should confirm.
Purchasing Business Premises for the Operating Business
Where commercial property is purchased to house an operating business (the borrower’s own business or a related business that pays commercial rent), the deductibility analysis depends on how the structure is structured. If the property is owned in a related entity and rented to the operating business at commercial rates, the interest may be deductible against the rental income received. If the property is owned directly by the operating business, the interest is generally deductible against the business’s trading income. The optimal structure depends on broader tax-planning and asset-protection considerations, beyond simple deductibility.
Funding Business Operations and Equipment
Where the borrowing is used to fund business operations (working capital, equipment purchases, expansion costs, debt consolidation within the business), the interest is generally deductible against the business’s trading income. The connection between borrowing and income production lies in the business’s overall income-generating activities. Specific deductibility may depend on the business structure, the nature of the equipment, and the proportion of business versus private use.
Refinancing Existing Income-Producing Loans
Where existing income-producing loans are refinanced, the deductibility position of the original loan generally carries through to the refinanced loan. A loan originally taken to purchase investment property remains deductible after refinance, provided the new loan replaces the old loan and the underlying income-producing use continues. This is a well-established principle, but the specific application depends on how the refinance is structured.
Cash-Out Refinance and Equity Release
Where a commercial property is refinanced with cash-out, the deductibility of interest on the released equity depends on how the released funds are used. Funds used for income-producing purposes (additional property investments, business expansions, share purchases for dividend income) typically support the continued deductibility of that portion. Funds used for private purposes (lifestyle, family holiday, private home renovation) typically aren’t deductible for that portion. This creates a mixed-purpose loan, with complex record-keeping requirements.
Mixed Purpose Loans and Apportionment
Mixed-purpose loans are among the most complex areas of interest deductibility and among the most common sources of error for borrowers managing their own tax affairs. The general principles are worth understanding, but the practical application strongly requires professional tax advice.
What Creates a Mixed Purpose Loan
A mixed purpose loan exists when a single loan facility has been used for both income-producing and non-income-producing purposes. Common scenarios: an investment loan where some funds have been redrawn for private purposes; a cash-out refinance where part is for business and part for personal use; a line of credit where multiple drawings have been made for different purposes; an original investment loan that has been partially repaid and then redrawn for private purposes.
The Apportionment Principle
Where a loan is for mixed purposes, the interest must be apportioned between the income-producing and non-income-producing components. Only the income-producing portion is deductible. If $400,000 of a $700,000 loan is used for income-producing purposes and $300,000 for private purposes, approximately 57% of the interest may be deductible (depending on specific timing and circumstances). The apportionment can change over time as repayments are made, requiring ongoing tracking.
The Tracing Method
The ATO’s general approach to mixed purpose loans involves tracing how the borrowed funds were actually used. Where the borrower can demonstrate the specific use of specific funds, the apportionment can be done with reasonable accuracy. Where the records are incomplete, or the funds are commingled, the ATO may apply more conservative apportionment methods. Detailed records of how each drawing was used are essential for supporting the deductibility position.
The Repayment Allocation Issue
When the borrower makes repayments on a mixed-purpose loan, the ATO generally treats repayments as being applied proportionally to both the income-producing and non-income-producing portions. The borrower cannot direct repayments specifically to the non-deductible portion to preserve deductibility on the income-producing portion. This is a common source of confusion and a reason why separating mixed-purpose drawings into separate loan facilities can be tax-effective.
Why Separate Loan Facilities Help
Where possible, structuring different purposes through different loan facilities simplifies the tax treatment significantly. A dedicated loan for the investment property purchase is fully deductible; a separate loan for personal purposes is clearly non-deductible. Combining them into one mixed-purpose loan creates ongoing complexity that can persist for decades. An accountant should advise on the optimal structure before settlement, particularly for borrowers considering cash-out refinance or other mixed-use scenarios.
What Affects Deductibility over Time
Deductibility is not necessarily fixed at the loan’s settlement; it can change over time as the borrower’s circumstances change. Several scenarios commonly affect the deductibility position over the life of the loan.
Change in Property Use
If a property’s use changes (from a rented investment property to an owner-occupied private residence, for example), the deductibility of the loan secured against it changes accordingly. Interest on the loan ceases to be deductible from the point the property stops being used for income production. The reverse can also happen: a property previously owner-occupied that is later let out commercially produces interest deductibility from the point the income-producing use begins.
Refinance Mid-Loan
Refinancing an income-producing loan generally preserves the deductibility position of the original loan, provided the new loan replaces the old loan, and the income-producing use continues. However, if the refinance includes cash-out for non-income-producing purposes, the new loan becomes a mixed-purpose loan with the consequences described above. The structure of the refinance significantly affects the ongoing tax outcome.
Sale of the Income-Producing Asset
If the income-producing asset is sold but the loan is not fully repaid, the deductibility of the remaining loan balance depends on how the sale proceeds are used and what the loan continues to fund. If the proceeds are used to repay the loan, the loan is discharged. If only part of the proceeds repays the loan, the residual balance may or may not retain deductibility depending on circumstances. Personalised tax advice at the point of sale is essential.
Capitalisation of Interest
Some loans allow interest to be capitalised (added to the loan balance rather than paid). The deductibility of capitalised interest involves additional rules. Capitalised interest on income-producing loans is generally treated as additional borrowing for the same purpose, which can preserve deductibility, but there are anti-avoidance rules and specific requirements to navigate. This is another area where professional advice is essential before structuring.
Records and Documentation
Supporting the deductibility position requires comprehensive records. The ATO can request evidence of how borrowed funds were used; borrowers who cannot produce this evidence may face challenges to their deductibility claims. Several categories of records are particularly important.
Loan Documentation
Original loan offer, loan agreement, security documents, and any subsequent variations. The loan documents establish the framework within which the deductibility analysis sits. Records should be retained for at least the life of the loan, plus any applicable record-keeping period under tax legislation (generally 5 years from the date the return is lodged).
Evidence of Fund Use
Records showing how the borrowed funds were actually used: settlement statements showing funds applied to property purchase, bank statements showing transfers to business accounts or specific investments, invoices for equipment purchased, and contracts evidencing business operational expenses. The clearer the trail from borrowing to income-producing use, the stronger the deductibility position.
Mixed-Use Tracking
For mixed-purpose loans, ongoing records showing how each drawing was used, when, and for what purpose. Spreadsheets tracking the apportionment over time may be needed. This is one of the most onerous record-keeping requirements in tax practice; many borrowers underestimate it until they are challenged.
Annual Records
Each financial year, records of interest paid, loan balance, any changes in use, and the apportionment applied. The annual tax return position should be consistent with the underlying records, and the records should be maintained in a form that supports an audit if required. An accountant typically helps maintain these records, but the borrower’s organisation supports the accountant’s work.
Common Edge Cases and Traps
Several specific scenarios recur as common areas where borrowers misunderstand or miss the deductibility consequences. Each of these should be discussed with a tax adviser before action is taken.
Using Redraw for Private Purposes
A loan originally taken for the purchase of an investment property has a redraw facility. The borrower redraws funds for a private purpose (home renovation, family holiday). The redrawn amount is treated as a new borrowing for a non-income-producing purpose, converting the loan into a mixed-purpose facility. The deductibility of interest on the redrawn portion is lost. This is one of the most common errors borrowers make in managing investment loans.
Offset Account vs Redraw
Offset accounts work differently from redraw facilities for tax purposes. Funds held in an offset account remain the borrower’s funds and reduce the interest charged on the loan without affecting the loan balance. Funds redrawn from a loan are new borrowing, with consequences for deductibility. Where the property is income-producing, using an offset account rather than redraw typically better preserves deductibility. This is a structural decision worth discussing with an accountant.
Property Held in Multiple Entities
Where commercial property is held by a single entity (a trust, company, or SMSF) and rented to a related entity (the operating business), the deductibility analysis can become complex. The interest on the property-owning entity may be deducted against rental income; the rental expense in the operating business may be deducted against trading income. Getting the structure right requires careful planning with a tax adviser.
Partial Income-Producing Use
Where a property has both income-producing and non-income-producing components (a building used partly for the owner’s business and partly rented to third parties; a property that is partly vacant and not actively rented), the interest deductibility may need to be apportioned accordingly. The specific apportionment depends on the facts; rough estimates are not generally acceptable. An accountant should advise.
Vacancy Periods
When an income-producing property is vacant between tenants but the owner is genuinely trying to re-let, interest deductibility generally continues. When the property is taken off the market or is not genuinely available for rent, the deductibility position changes. Documentation of marketing efforts during vacancy periods supports the continued deductibility position.
Personal Guarantees and Indemnities
Where a director provides a personal guarantee for a company’s borrowing and is later called on under the guarantee, the tax treatment of the payment depends on the specific circumstances. The director may have rights of recovery against the borrower; the payment may or may not be deductible to the director directly. This is a specialist area where tax advice is essential.
A Worked Example: Mixed Purpose Loan Apportionment
To illustrate how a tax adviser might approach a mixed-purpose loan situation, consider a hypothetical scenario. The figures below are illustrative; the specific outcomes for any borrower depend on their circumstances and require personalised advice.
The Starting Position
A borrower has a $1.2 million commercial property loan, originally taken to purchase tenanted commercial property at 70% LVR. The property produces $90,000 in net rental income annually. The original loan is at 6.5% with an annual interest of approximately $78,000. Initially, the loan is for a single purpose (acquiring income-producing property), and the interest is generally fully deductible against the rental income.
The Cash-Out Refinance
Three years later, the borrower refinances to $1.5 million through a cash-out refinance. The additional $300,000 is split: $200,000 used to acquire a portfolio of investment shares (which produce dividend income); $100,000 used to renovate the borrower’s private residence.
The Apportionment Analysis
After refinancing, the $1.5 million loan has three potential portions: $1.2 million for the original commercial property (income-producing), $200,000 for share investment (income-producing), and $100,000 for private renovation (non-income-producing). Total income-producing portion: $1.4 million / $1.5 million = approximately 93%. Approximately 93% of the interest may be deductible (against the combined rental and dividend income); approximately 7% may not be deductible. Specific apportionment depends on timing and other circumstances.
The Record-Keeping Obligation
From this point forward, the borrower needs to maintain records showing the apportionment, track repayments proportionally, and ensure the tax return treats the interest accordingly each year. The complexity persists for the loan’s life. If further drawings or repayments occur, the apportionment changes; records need to keep pace.
The Alternative Structure
A tax adviser might have recommended structuring the cash-out as two separate loan facilities rather than one mixed-purpose loan. Loan A: $1.4 million for income-producing purposes (clean deductibility). Loan B: $100,000 for private renovation (clean non-deductibility). This structure simplifies tax treatment significantly and reduces the ongoing record-keeping burden. The choice between mixed-purpose loan and separate facilities should be made before settlement with proper tax advice, not discovered later.
The Critical Caveat
The numbers and approach above are illustrative for explaining the principle. Every actual borrower’s situation depends on specific facts, entity structures, asset types, and other circumstances that affect the analysis. The numbers shown may or may not reflect what a tax adviser would conclude in any specific situation. This is exactly the kind of scenario where personalised advice from a qualified accountant or registered tax agent is essential.
Why You Need an Accountant or Tax Adviser
The principles in this article are general; their application to specific situations requires professional judgement. Several specific reasons make personalised tax advice essential for commercial loan structure decisions.
Complexity of the Rules
Interest deductibility is governed by sections of the Income Tax Assessment Act, multiple ATO Tax Rulings, and decades of case law. The rules are technical, with many specific provisions and exceptions. Lay readers cannot reliably apply the rules to non-standard situations without professional support.
Personal Circumstances Matter
The same loan structure can produce different tax outcomes depending on the borrower’s entity structure, other income sources, related party arrangements, and broader tax position. Generic articles cannot account for these variables; personalised advice can.
Anti-Avoidance Rules
The ATO has specific anti-avoidance provisions that can apply to arrangements primarily structured to obtain tax benefits. Some arrangements that look beneficial may be caught by these rules. A tax adviser can identify when an arrangement is at risk of these provisions and structure the transaction to avoid issues.
Audit and Substantiation
The ATO can audit deductibility claims and require borrowers to substantiate the basis. Borrowers who have structured arrangements with professional advice are better positioned in audit situations than those who have proceeded without advice. The accountant’s involvement also provides protection if the position is later challenged.
Cost-Benefit
Personalised tax advice on a substantial commercial transaction typically costs $500 to $2,500, depending on complexity. The potential tax consequences of getting the structure wrong on a $1 million-plus loan can be tens of thousands of dollars. The cost-benefit strongly favours seeking advice; this is not an area to economise on professional fees.
Finding the Right Adviser
Not every accountant is equally suited to commercial property and business tax matters. The right adviser has experience with commercial loans, understands the interaction between business structures and tax outcomes, and stays current with ATO rulings affecting commercial borrowers. The broader distinction between commercial and business loans, which affects deductibility analysis, encompasses some of the structural differences between commercial property loans and business loans that a qualified tax adviser would consider when assessing deductibility for any specific deal.
Practical Pointers for Tax-Effective Commercial Borrowing
Several practical habits support tax-effective commercial borrowing decisions. None of these substitutes for professional advice; all of them complement it.
Engage the Accountant Before Settlement
The accountant’s involvement is most valuable before settlement, when the structure can still be optimised. After settlement, options for restructuring are limited and may have their own tax consequences. Engaging the accountant during the lender negotiation phase, alongside the broker, produces the best outcomes.
Discuss Structure Options Specifically
Don’t ask the accountant ‘Is this deductible?’ Ask ‘what structure would optimise the tax treatment?’ The framing matters. The first question seeks confirmation of a structure you’ve chosen; the second seeks input into structure design. The second approach typically produces materially better outcomes.
Keep Detailed Records from Day One
Establish record-keeping practices at settlement: a folder for loan documents, evidence of fund use, ongoing interest payments, and any subsequent transactions affecting the loan. The discipline pays off when tax returns are prepared and especially if the position is ever audited.
Use Separate Loan Facilities for Different Purposes
Where possible, structure different purposes through separate loan facilities. This is one of the most effective tax-efficiency strategies available. Mixed-purpose loans create ongoing complexity that can persist for decades; separate facilities have clean treatment from the start.
Review the Position Annually
At each annual review, revisit the tax position with the accountant. Circumstances change; what was tax-effective at settlement may no longer be the optimal structure 5 years later. Annual review allows for course corrections before issues accumulate.
Avoid Using Investment Loan Redraw for Private Purposes
This is the single most common error borrowers make in managing investment loans. Using redraw from an investment loan to fund private purposes converts a clean income-producing loan into a mixed-purpose loan with permanent complexity. Where private funds are needed, source them from a separate facility or savings, not from the investment loan’s redraw.
Where to Read the ATO’s Guidance
The Australian Taxation Office provides authoritative guidance on interest deductibility through public rulings, individual advice services, and educational materials on its website. While the guidance is technical, the foundational principles are accessible to readers willing to engage with the material.
The Australian Taxation Office’s overview of interest deductibility and apportionment for mixed-purpose loans explains the core principle that only interest expenses incurred for income-producing purposes are deductible, and the apportionment requirement when borrowed money is used for both private and income-producing purposes. While the page is focused on investment income deductions generally, the underlying principle applies directly to commercial property and business loan interest. Reading this guidance alongside your own accountant’s advice helps borrowers understand the framework their adviser is applying.
Frequently Asked Questions (FAQs)
1. Is the interest on my commercial property loan deductible?
Generally, interest is deductible to the extent the borrowed funds were used to acquire or hold income-producing property. For tenanted commercial property producing rental income, the interest is typically deductible against that income. For owner-occupied business premises, deductibility depends on the entity structure and the rental arrangement. The specific position for any borrower depends on their circumstances and requires personalised tax advice. This article cannot answer the question for any specific situation.
2. Can I claim interest if my property is vacant?
Generally, yes, provided the property is genuinely available for rent, and the owner is making reasonable efforts to find tenants. Marketing the property, engaging leasing agents, and maintaining the property in lettable condition support the continued deductibility position. If the property is taken off the market or held without genuine efforts to let, deductibility may cease. Records of the marketing efforts during the vacancy are important for supporting the position.
3. What happens if I refinance my commercial loan?
Refinancing an income-producing loan generally preserves the deductibility position of the original loan, provided the new loan replaces the old loan and the underlying income-producing use continues. However, cash-out refinances, in which part of the new loan is used for non-income-producing purposes, create mixed-purpose facilities that entail ongoing complexity. The specific outcome depends on how the refinance is structured. Personalised tax advice before settlement is essential.
4. Can I claim interest if my company borrows money and I personally guarantee the loan?
Interest is generally claimed by the entity that incurs it, not the guarantor. If a company is the borrower, it claims the interest deduction (subject to its income position and deductibility principles). The guarantor’s role is contingent and does not typically create personal deductibility. If the guarantee is later called and the guarantor makes payments, the tax treatment of those payments depends on the specific circumstances and is a specialist area requiring tax advice.
5. What records do I need to keep?
At minimum: loan documents and any variations, settlement statements showing how funds were applied, ongoing interest statements from the lender, bank statements showing how funds moved after drawdown, and (for mixed-purpose loans) ongoing apportionment calculations. Records should be retained for at least 5 years from when the relevant tax return is lodged, though longer retention is sensible for loans with multi-year tax implications. An accountant can advise on specific record-keeping requirements for the situation.
6. Why do I need an accountant if you’ve explained the principles?
The principles explained in this article are general. Their application to any specific borrower depends on the entity structure, related-party arrangements, the specific transactions involved, the borrower’s other income, and many other factors. Generic principles cannot account for these variables; personalised advice can. Additionally, the ATO can audit and challenge deductibility claims, and borrowers with structured arrangements supported by professional advice are better positioned in audit situations. The accountant’s role is essential, not optional.
7. Should I use an offset account or pay extra into the loan?
For income-producing loans, offset accounts are often more tax-efficient than paying extra into the loan and then redrawing it later. Offset balances reduce interest expense without changing the loan balance; redrawing funds constitutes new borrowing and may affect deductibility if used privately. The specific decision depends on the loan terms, the borrower’s other circumstances, and broader financial planning. An accountant familiar with property loan structures should advise on the optimal approach.
The Bottom Line
Commercial loan interest deductibility depends on the purpose for which the borrowed funds are used, not on the security supporting the loan. Borrowing for income-producing purposes (commercial property leased to tenants, business operations, dividend-producing investments) generally produces deductible interest; borrowing for private or non-income-producing purposes generally does not. Mixed-purpose loans create apportionment requirements and complex record-keeping obligations that persist for the loan’s life. Refinancing, change in property use, and cash-out refinance all affect the deductibility position over time.
For every commercial borrower, the smartest approach is to engage a qualified accountant or registered tax agent before the loan is settled, structure the borrowing to optimise the tax treatment from the start, keep detailed records from day one, and review the position annually as circumstances change. The principles in this article are general; their application to any specific situation requires personalised advice. Tax advice on a substantial commercial transaction is one of the highest-return professional services available; the cost is small relative to the consequences of getting the structure wrong. Treat the tax dimension of commercial borrowing with the same diligence as the loan structure itself, and engage professionals to support the decision.
