How Banks Assess Investment Borrowing Capacity

Borrowing capacity for investment property loans is the maximum amount a lender is willing to let you borrow, based on your financial situation and their credit policy. For investors, this figure determines how much you can put toward purchasing a property and, in turn, how your portfolio can grow.

Banks calculate this figure using their own models, and while the numbers vary between lenders, the principles are broadly similar.

Income and Employment Stability

Lenders prefer steady, reliable income. For investors, this usually includes salary, business income, or contract work. Most banks also include other income streams, such as dividends, bonuses, or government benefits, but may shade them down (i.e. only accept a percentage).

Existing Debts and Commitments

Your current mortgage, personal loans, credit cards, and even buy now–pay later facilities reduce your capacity. Even unused credit card limits are included in the assessment, as banks assume you could spend that money at any time.

Rental Income and Shading Policies

Rental income is key to investment borrowing power. However, banks typically use only 70–80% of the rental income (a practice called “shading”) to allow for vacancy, maintenance, and management costs. For example, if your property earns $500 per week, a bank may only count $350–$400 in their calculation.

Living Expenses and Household Costs

Banks compare your declared living expenses with the Household Expenditure Measure (HEM) benchmark. If your spending is above the benchmark, they use your actual figure. This can reduce borrowing capacity for families with higher ongoing costs.

Interest Rate Buffers and Assessment Rates

Banks apply a buffer, currently at least 3% above the actual rate, to ensure you can afford repayments if rates rise. For example, if the loan rate is 6%, your capacity is assessed at 9%. This conservative approach can significantly reduce borrowing power, but it also protects you from overextending.

Pros:

• Helps protect borrowers from over-borrowing
• Encourages responsible lending and financial stability
• Accounts for changes in interest rates and costs

Cons:

• Conservative shading policies can reduce your actual borrowing power
• Different banks use different models, making comparisons tricky
• Doesn’t always reflect real-world cash flow for investors

Your borrowing capacity directly impacts how quickly you can grow your property portfolio. For example:

• An investor with a $120,000 income and moderate expenses may qualify for a $700,000 loan.
• By restructuring debts or optimising rental income, that same investor might unlock an additional $100,000 in borrowing power.

Understanding the rules gives you an edge. A skilled mortgage broker can match you with lenders whose policies suit your situation—such as those more generous with rental income or who use lower expense benchmarks.

• Reduce unnecessary debts – Pay off personal loans and cut unused credit card limits.
• Optimise living expenses – Track and manage household spending.
• Choose the right lender – Each bank has different shading and assessment rules.
• Leverage equity – Use existing property equity to strengthen your application.
• Work with a broker – Expert guidance helps position your finances in the best light.

Banks use strict models to assess borrowing capacity, but these aren’t set in stone. With the right strategy—reducing liabilities, maximising rental income, and choosing the right lender—you can significantly improve your investment opportunities.

(No cost, no obligation — just friendly advice.)