Updated 7 November 2026 (Australia/Sydney).
A growing property portfolio brings additional repayment commitments as well as potential rental income. Having equity does not establish that another loan is affordable. Before looking for the next purchase, review what the existing portfolio requires from your household and how another property would change that position.
Start with a portfolio record
Create one record showing each property’s loan balance, repayment, interest type and remaining term. Add the end dates of fixed and interest-only periods. Alongside those details, record rent actually received and the costs you pay, rather than relying only on advertised rental estimates.
Include council and water rates, insurance, strata charges where applicable, management fees and maintenance. A property may be vacant or its rental income may not cover all costs. Tax deductions, where available, do not remove the need to meet expenses when they fall due. Moneysmart also warns that property values can fall and that buying and selling involves substantial costs. (Moneysmart: Buying an investment property)
Understand the lender’s assessment
The amount a lender is prepared to advance is distinct from the equity in a property and from your own comfort with repayments. APRA’s residential mortgage standard requires banks covered by the standard to assess serviceability using an interest-rate buffer. That assessment is a risk check, not a promise that the resulting maximum would suit your plans. (APRA: APS 220 Credit Risk Management)
Ask the proposed lender or broker how income, existing debts and expenses have been treated. Request the assumptions in a form you can review. If a figure appears incorrect, correct the evidence rather than trying to work around the assessment. Do not assume a previous approval remains valid after another purchase or a change in employment.
Plan for loan transitions
Interest-only repayments do not reduce the principal during the interest-only period. When principal repayments begin, the required payment increases. Compare that future payment with your expected budget before considering another acquisition. An interest-only structure should not be presented as a guaranteed way to unlock more borrowing capacity. (Moneysmart: Interest-only home loans)
Put all upcoming loan changes on a calendar and look for dates that cluster together. For example, ask what your budget would look like if a fixed period ended around the same time as a tenancy. This is a planning scenario, not a forecast that either event will cause difficulty.
Test the next purchase against your own limits
Prepare a before-and-after budget and a separate scenario with lower rent or a period without tenants. Decide what cash reserve you would want available and which discretionary spending could genuinely change. Do not count the same reserve as both the next deposit and money available for emergencies.
Take the complete portfolio record to your lending discussion and seek qualified advice on ownership and tax questions. If the proposed purchase leaves too little room for repairs, household needs or changing repayments, delaying it is an option worth evaluating.
This is general information, not a recommendation to buy property or maximise debt. Lending criteria and individual circumstances determine available borrowing.