That's where people go wrong. They see interest on a business-linked facility and assume it all counts. The ATO looks at what each draw paid for, not what the account is called or what secures it.
This guide covers purpose tests, mixed-use apportionment, how fees are treated separately, and the records you need. It's general information only, not personal tax advice.
Key Takeaways
- What you spent each draw on matters more than the facility type or security.
- Private spending, principal repayments and unsupported mixed-use portions aren't automatically deductible.
- Interest, principal and borrowing fees are treated separately.
- Statements, invoices and an apportionment schedule are your evidence.
What Determines Whether Line-of-Credit Interest Is Tax Deductible in Australia?
The purpose and income connection matter most
Under section 8-1 of the ITAA 1997, an expense is deductible if it's incurred in gaining or producing assessable income, or necessarily incurred in carrying on a business for that purpose. Capital, private and domestic outgoings are excluded. The loan principal and its interest are separate expenses.
The same facility can produce different results:
- A draw for inventory, wages or supplier invoices has a business connection.
- A draw for a family holiday doesn't, even if the account sits with your business bank.
Private, business and investment use
Each type of borrowing is tested on its own use:
- Business: interest on borrowing to buy income-producing assets, fund operations or meet current expenses can qualify.
- Rental property: interest on funds used to buy, renovate or run a rental can qualify, excluding private-use periods.
- Shares: interest qualifies where assessable dividends are reasonably expected.
- Private: no deduction.
Your entity type changes where you report it, not whether the purpose test applies.
Security doesn't decide the outcome either. Under TR 2000/2, deductibility follows the use of funds, not the asset securing the loan. Borrowing against your home to buy a private car gives no deduction. Borrowing against your home to buy shares can.
Mixed-purpose and changing use
Each draw or redraw is treated as a separate borrowing. If one facility funds both deductible and private items, you trace each draw and claim only the income-producing share. You can't claim the whole balance.
Complications arise when you:
- Make repayments: under TR 2000/2, they generally reduce the income-producing and private portions proportionately. You can't nominate them against private debt only.
- Redraw: the new use is tested afresh.
- Refinance: this doesn't erase an existing private component.
A mixed debt can be split into separate accounts matching its existing income and private portions.
Which Line-of-Credit Uses Usually Qualify, and Which Usually Do Not?
Business and working-capital uses
Interest on Australian borrowings used to buy income-producing business assets, finance operations or meet current business expenses is generally deductible. Sole traders report this at P8 Q of the business schedule.
Keep the interest and the purchase apart. Interest can be deductible while the item bought follows its own rules: stock, depreciation or capital expenditure. Wages and rent are deductible in their own right, separate from how you funded them.
Investment and income-producing property uses
For rentals, interest on acquisition and improvement borrowing can qualify. Some points to watch:
- Interest before the first rental income can qualify if the income-producing intent is genuine and ongoing (TR 2004/4). A dormant venture doesn't.
- From 1 July 2019, section 26-102 can deny holding costs, including interest, on vacant land.
- A rental loss, including eligible interest, can offset other income such as salary. Unabsorbed losses can be carried forward.
Security and purpose are separate questions. Zac and Lucy, in the ATO's example, borrowed $400,000 against their rental to buy a new private home. That interest isn't deductible.
Private and non-income-producing uses
Household spending, holidays, personal education and private debt aren't deductible. Running the money through a business account doesn't change that. The ATO's October 2026 rental-errors statement flags private school fees and holidays funded by rental-loan redraws as a current compliance focus.
Practical examples
These are hypothetical and don't promise any tax saving.
- Wholly business: a café owner draws $30,000 to pay suppliers and wages. The interest on that draw is generally claimable.
- Wholly private: a draw of $15,000 for a holiday. The interest isn't deductible.
- Mixed: following the ATO's example, Yoko borrows $400,000: $380,000 for a rental, $20,000 for a car. Of $35,000 interest, the ATO allows $33,250.
How to Calculate, Document, and Claim the Deduction
Separate interest, principal, and other charges
Use lender statements to isolate interest. Keep it apart from principal repayments, late charges and account administration costs. Only the interest portion goes in the claim.
"Incurred" means a presently existing, inescapable liability, not simply cash paid (TR 97/7).
Prepaid interest may qualify for immediate deduction under the 12-month rule for eligible taxpayers. Otherwise it is spread. Confirm your position with an adviser.
Review fees and borrowing costs separately
Borrowing costs fall under section 25-25. They're deductible only to the extent the borrowing produces assessable income. Spread them over the shorter of five years and the loan term. Costs of $100 or less can be deducted immediately.
Typical borrowing expenses include:
- Establishment fees
- Lender-required valuations
- Mortgage document legal costs
- Broker fees
- Lender's mortgage insurance
- Stamp duty on the mortgage
Stamp duty on a property transfer and conveyancing on the purchase are capital costs, not borrowing expenses. Ongoing bank charges may be deductible in the year incurred, but not every fee called an "annual facility fee" qualifies for an immediate deduction.
Trace every draw and calculate any apportionment
Use a separate account or clear accounting codes for line-of-credit proceeds. Build a schedule linking each draw to the invoice, asset or private expense it funded.
For daily-accruing interest, the deductible amount follows the income-producing share of the daily balance. TR 2000/2 also accepts a monthly method:
Monthly interest × (opening + closing income-producing principal) ÷ (opening + closing total principal)
Have a tax professional review complex redraws, refinancing or shifting balances.
Keep evidence that supports the original purpose
Retain:
- Loan agreement and lender statements
- Drawdown and repayment history
- Bank statements, invoices and contracts
- Investment or property records
- Business accounts and your apportionment method
Records must show both the interest incurred and how the funds were used. The ATO generally requires business records for five years, though losses, assets and disputes can require longer.
Claim the correct amount in the relevant return
For 2025-26 returns:
| Taxpayer | Where interest goes |
|---|---|
| Individual, rental | Question 21, label Q |
| Individual, shares | D7 or D8 |
| Sole trader | P8 Q (Australian), P8 R (overseas) |
| Company | Item 6 V (Australian), item 6 J (overseas) |
| Trust | Item 5 I (business), item 9 G (rental) |
| Partnership | Partnership return, item 5 |
Don't claim principal, private interest or unsupported fees. Reconcile the claim to annual lender statements and your accounting records.
Common Mistakes and a Practical Compliance Checklist
Frequent errors:
- Assuming all line-of-credit interest is deductible
- Treating the facility limit as borrowed money (only drawn funds count)
- Claiming full interest on a mixed-use account
- Confusing principal with interest
- Claiming ATO interest charges: GIC and SIC incurred on or after 1 July 2025 are non-deductible
Year-end checklist:
- List every draw and classify its purpose.
- Reconcile interest to lender statements.
- Review fees under the borrowing-cost rules.
- Update your apportionment calculation.
- Store supporting records.
- Check current ATO guidance.
For Australian businesses with India operations, VJM Global provides accounting outsourcing, BAS processing, tax compliance support and management reporting. These services help organise multi-entity records and coordinate with your Australian tax adviser. They do not guarantee deductibility or replace personalised advice.
Frequently Asked Questions
Is late payment interest tax deductible?
Interest on an income-producing or business liability may be deductible. GIC and SIC from the ATO incurred on or after 1 July 2025 aren't, and statutory penalties generally aren't either. Check the current ATO position.
Can I deduct loan fees?
It depends on the fee's nature and whether the borrowing produces assessable income. Many borrowing costs are spread over up to five years, while some ongoing charges are claimed in the year incurred.
Can I deduct mortgage interest on my taxes?
Not on your own home. Australia has no blanket owner-occupied mortgage interest deduction, unlike US itemisation rules. Interest on borrowing for an income-producing property can qualify.
What is the tax relief available for house loans?
Relief depends on purpose and structure. Private home-loan interest isn't deductible, while borrowing for a rental can be. See current ATO guidance for your situation.
Is interest on a business line of credit tax deductible in Australia?
Often, yes. Assess each draw's use, its connection to business income, any private portion and the records supporting the claim.
How do I apportion interest when a line of credit has business and private uses?
Trace withdrawals and repayments, then calculate the deductible share using a consistent, supportable method such as the ATO-accepted monthly formula. Get professional advice for complex or changing transactions.
