How much can we borrow?

Why two lenders give different ceilings

The serviceability calculator behind every lender is different. They differ on how they treat overtime, bonuses, child-care, HELP debt, credit card limits (committed vs declared), and dependents. The same household can be quoted around $850K at a major bank and closer to $1.05M at a second-tier lender on the panel.

The APRA buffer

APRA expects lenders to assess your repayments at the product rate plus a 3.0 percentage-point buffer. So if you enter 5.79% p.a., the serviceability calc tests you at 8.79% p.a. — we apply the same buffer here. The buffer is added to your existing debts too, and it bites hardest on the third or fourth property. Lenders also work off the higher of your declared living expenses and a HEM benchmark, so under-stating spending rarely lifts the number.

Debt-to-income limits

From 1 February 2026, APRA caps each lender so that no more than 20% of new lending can sit at a debt-to-income ratio of 6x or higher. As a rough guide, total borrowing capacity tends to land around 5–6x household income before that ceiling and the serviceability buffer start to bite.

When the buffer locks you in

The same 3.0pp buffer that protects new borrowers can trap existing ones: assessed at the higher rate, your current loan may no longer "fit" another lender even though you're paying it on time. For a like-for-like refinance that lowers your rate and repayments and clearly improves your position, some lenders apply a reduced or zero serviceability buffer where your repayment history is clean and the new loan is still affordable — it isn't automatic, and APRA still expects lenders to be prudent, but it can free a borrower the buffer would otherwise hold in place. Investors can often lift capacity by moving existing loans to interest-only with a lender that assesses the actual repayment rather than a buffered figure. A broker can tell you which lenders on the panel apply this and whether it suits your file.