How Extra Income Can Affect Borrowing Power

Updated 4 September 2026 · 5 min read

Why lenders assess extra income differently

Borrowing capacity is based on income a lender believes is likely to continue while the loan is being repaid. Extra income can help, but a lender may take a cautious view where it is new, irregular, seasonal or difficult to verify. Its treatment is part of each lender's credit policy, so there is no universal percentage that BorrowPower can responsibly apply.

Income types that may need a closer look

• Overtime, bonuses and commissions: can move with hours, targets or the employer's trading conditions.
• Rental income: can be affected by vacancy, lease terms and property costs.
• Casual work and a second job: may depend on a consistent work pattern and employment history.
• Self-employed or freelance income: can vary between financial years and may need business records as well as personal income evidence.
• Short-stay income: can be especially variable because occupancy and platform income can change quickly.

What evidence is commonly useful

The exact documents depend on the lender and income type. Relevant records can include payslips, employment contracts, tax returns, notices of assessment, business financials, bank statements, leases or rental-agent information. Keep records that show both the amount and the history of the income; do not assume an estimate or a future opportunity will be treated as ongoing income.

Use a cautious scenario, not a promise

Use the BorrowPower calculator to understand the direction of change, then test a cautious version of your budget. For example, use only income you can document and increase expenses for a possible vacancy, quieter work period or new commitment. The result remains a planning estimate, not a lender decision.

Practical next steps

• Use a separate account for rental or side-income deposits.
• Keep relevant records, including leases, booking reports, tax summaries and payslips.
• Ask the lender or broker how the specific income type is assessed before relying on it in an offer.
• Run the Borrowing Power Calculator with your documented income, then compare a more cautious scenario.

Sources and review

Last reviewed 4 September 2026. BorrowPower does not publish lender-specific income shading because policies and evidence requirements change. See the data and methodology page for the calculator's own assumptions and limits.