The fourth property, not the first.

By the third or fourth property, the binding constraint is rarely savings. It's APRA's debt-to-income ratio cap (most banks now reject DTI >6×) and the lender's specific policy on existing-portfolio rental income (some discount it 60%, some 80%). Different lenders unlock materially different next-purchase capacity.

Equity-pull strategy: refinance one or two existing properties at 80% LVR to extract deposit for the next, ideally without cross-collateralising (each property stands alone as security). Cross-collateralisation simplifies application but hands the lender too much control at a future stress point.

What we model: portfolio-aware buying-power (existing-rental-income credited at conservative 60-80%), 10-year cashflow with rate-stress across the whole portfolio, CGT positioning if you sell one to deleverage, and the per-state land-tax threshold each property crosses.