How to Use Rental Income to Boost Your Borrowing Power for Investment Properties

Understanding how lenders treat rental income is crucial for property investors looking to expand their portfolio. Whether you already own an investment property or are planning to purchase one, the way a lender assesses your rental income can significantly impact your borrowing capacity. This guide delves into the mechanics of rental income assessment, strategies to maximize your borrowing power, and the documentation you need to present a strong application.


Why Rental Income Matters for Borrowing Power

When you apply for a home loan, lenders calculate your borrowing capacity based on your income, expenses, debts, and the loan’s terms. For investment properties, rental income is a key component that can boost your serviceability. However, lenders don’t simply add the full rental amount to your income. They apply a “shading” or “haircut” to account for vacancies, management fees, maintenance, and other holding costs. This conservative approach ensures you can still meet repayments if your rental income fluctuates.

The Role of Rental Income in Serviceability

Serviceability is a measure of your ability to repay a loan. Lenders use either the Household Expenditure Method (HEM) or their own benchmarks to estimate living expenses, and then compare your net income (after tax) to the loan repayments and other commitments. Rental income is added to your assessable income, but only after deductions. Understanding how each lender calculates this can help you choose the right loan product.

How Australian Lenders Assess Rental Income

Australian lenders vary in their treatment of rental income, but most follow similar principles. They typically distinguish between existing rental income (from properties you already own) and potential rental income (for a property you’re about to purchase).

Existing Rental Income

For properties already generating rent, lenders will look at your tax returns or a current lease agreement. The most common approach is to use a percentage of the gross rental income, often around 75% to 80%. For example, if your property earns $500 per week in rent, a lender might assess $400 per week as income. This shading covers expenses like property management fees (typically 7-10% of rent), council rates, insurance, repairs, and a vacancy allowance.

Some lenders may instead use the net rental income from your tax return, adding back non-cash deductions like depreciation. This can be beneficial if your property is highly geared and shows a taxable loss, as the added-back depreciation can increase your assessable income. However, lenders will still apply a vacancy factor.

Potential Rental Income for New Purchases

When you’re buying a new investment property, lenders will estimate the rental income based on a rental appraisal from a licensed real estate agent. This appraisal should be on the agent’s letterhead and include details of comparable properties. Lenders typically accept 100% of the appraised rent but then shade it by the same percentage (e.g., 75-80%) to arrive at the assessable income.

It’s important to note that some lenders cap the rental income they’ll consider, especially for high-end properties or in regions with volatile rental markets. They may also cross-reference the appraisal with their own data or require a second opinion if the figure seems inflated.

Lender-Specific Policies

Not all lenders are the same. The table below compares how different types of lenders treat rental income:

Lender Type	Existing Rental Income Assessment	New Purchase Rental Income	Notes
Major Banks (e.g., CBA, Westpac)	75-80% of gross rent, or net rent plus depreciation add-back	75-80% of appraised rent	Strict with documentation; may require tax returns and lease agreements.
Non-Bank Lenders (e.g., Pepper, Liberty)	Up to 80% of gross rent, sometimes higher if strong lease history	Up to 80% of appraised rent	More flexible with credit-impaired borrowers but may charge higher rates.
Specialist Investment Lenders	May use 100% of net rent from tax return with add-backs	May use 100% of appraised rent then shade	Often cater to experienced investors with multiple properties.
Online Lenders (e.g., Athena, Tic:Toc)	Typically 80% of gross rent	80% of appraised rent	Fast approval but stricter automated credit checks.

Note: Policies can change. Always check with a broker or lender for current terms.

Documentation Required to Prove Rental Income

To get the best assessment, you must provide solid evidence of rental income. The requirements differ for existing and new properties.

For Existing Investment Properties

• Lease Agreement: A current, signed tenancy agreement showing the rent amount and lease term.
• Rent Statements: Recent bank statements showing rent deposits (usually the last 3-6 months).
• Tax Returns: Your latest tax return with the rental schedule (if you’ve owned the property for a full financial year).
• Property Manager Statements: If using an agent, provide statements showing rent collected and expenses deducted.

For a New Purchase

• Rental Appraisal: A letter from a licensed real estate agent detailing the expected weekly rent, comparable properties, and the agent’s credentials.
• Market Evidence: Some lenders may ask for recent rental listings or sales data to support the appraisal.

Tips for Strong Documentation

• Ensure the rental appraisal is realistic. If it’s too high, the lender may reduce it, affecting your borrowing capacity.
• If you’re self-managing, keep meticulous records. Lenders may scrutinize self-managed properties more closely.
• For short-term rentals (e.g., Airbnb), many lenders will not accept this income unless it’s through a specialized lender. Long-term leases are preferred.

Strategies to Maximize Borrowing Capacity with Rental Income

Even with lender shading, there are ways to optimize how your rental income contributes to your borrowing power.

1. Choose the Right Lender

Different lenders have different shading percentages and policies. A mortgage broker can help you find lenders that are more generous with rental income. For instance, some lenders use 80% shading, while others use 75%. On a $30,000 annual rental income, that 5% difference adds $1,500 to your assessable income, which could mean tens of thousands in extra borrowing capacity.

2. Minimize Other Debts

Rental income is just one part of the serviceability equation. Reducing credit card limits, paying off personal loans, and consolidating debts can free up more capacity. Lenders assess your total liabilities, so every dollar counts.

3. Opt for Interest-Only Loans

Interest-only (IO) repayments can significantly improve cash flow and serviceability in the short term. By paying only the interest, your monthly commitment is lower, allowing you to borrow more. However, IO periods are typically limited to 5 years, and you’ll need a plan for when they revert to principal and interest.

4. Leverage Depreciation Benefits

If you use the net rental income method, depreciation add-backs can increase your assessable income. A tax depreciation schedule from a quantity surveyor can maximize this benefit. Note that only certain lenders allow depreciation add-backs, so confirm before applying.

5. Fix Your Interest Rate

Fixing your interest rate can give lenders certainty about your future repayments. When assessing serviceability, many lenders apply a buffer (e.g., 3% above the actual rate) to ensure you can handle rate rises. If you fix at a lower rate, the assessable rate may be lower, improving your borrowing capacity.

6. Use a Rental Guarantee (If Available)

Some off-the-plan properties come with rental guarantees from the developer. While not all lenders accept these, some may use the guaranteed amount instead of an appraisal. This can be advantageous if the guarantee is higher than market rent.

Common Pitfalls to Avoid

While rental income can boost your borrowing power, there are traps that can reduce it or lead to loan rejection.

Overestimating Rental Income

Inflated rental appraisals can backfire. Lenders have access to market data and may independently verify the figure. If they deem it unrealistic, they’ll use a lower amount, potentially sinking your application.

Ignoring Holding Costs

Even if you don’t claim all expenses on your tax return, lenders will factor in statutory costs like rates, insurance, and maintenance. If your property is negatively geared, the net rental loss can reduce your overall income. Always calculate the net impact before applying.

Short-Term Rental Dependence

If you rely on Airbnb or holiday letting, most mainstream lenders won’t consider this income. You’ll need to demonstrate a long-term lease or use a specialist lender, often at a higher rate.

Not Disclosing All Properties

When you apply for a loan, you must declare all investment properties and their associated debts. Hiding a property or its expenses can be considered fraud and will likely be discovered through credit checks.

The Future of Rental Income Assessment

In 2025, with fluctuating interest rates and rental markets, lenders are becoming more cautious. However, the strong rental growth in many Australian cities (with some areas seeing 10-15% annual increases, according to CoreLogic data) means rental income is more valuable than ever. Lenders may adjust their shading percentages or introduce more granular assessments based on location and property type.

Digital verification tools are also streamlining the process. Open banking allows lenders to see your rent credits in real time, reducing the need for paper statements. This could lead to faster approvals and more accurate assessments.

FAQ

What percentage of rental income do most lenders use?

Most Australian lenders use 75% to 80% of gross rental income to account for expenses and vacancies. Some may use net rental income from tax returns with depreciation added back.

Can I use potential rental income for a property I haven’t bought yet?

Yes, lenders will accept a rental appraisal from a licensed real estate agent for a new purchase. They then apply the same shading percentage to estimate assessable income.

Do all lenders treat rental income the same way?

No, policies vary. Some lenders are more generous with shading percentages or allow depreciation add-backs. It’s important to compare lenders or use a broker to find the best fit.

How can I increase my borrowing capacity with rental income?

Choose a lender with higher shading, reduce other debts, consider interest-only repayments, and provide strong documentation like a realistic rental appraisal and clean rent statements.

Will short-term rental income (Airbnb) be accepted?

Most mainstream lenders do not accept short-term rental income. You’ll need a long-term lease or a specialist lender that considers holiday letting, often at a lower percentage and higher interest rate.

References

1. Australian Securities and Investments Commission (ASIC) - Responsible Lending Guidelines, 2024 update. https://asic.gov.au/regulatory-resources/credit/responsible-lending/
2. CoreLogic Australia - Rental Market Update, March 2025. https://www.corelogic.com.au/news-research/reports/rental-market-update
3. Australian Taxation Office - Rental Property Expenses, 2024-25. https://www.ato.gov.au/individuals-and-families/investments-and-assets/rental-property/rental-property-expenses
4. Mortgage and Finance Association of Australia (MFAA) - Industry Report on Lending Standards, 2025.
5. Reserve Bank of Australia - Statement on Monetary Policy, February 2025, referencing housing credit conditions. https://www.rba.gov.au/publications/smp/2025/feb/