Single vs couple: how your application changes borrowing power
Last updated September 2026 · Back to the calculator · All guides
Applying with a partner usually lifts how much you can borrow, but not by simply doubling it. Lenders combine both of your incomes, and they also combine both of your debts, expenses and credit histories.
What a second applicant adds
- A second income, which lifts the amount you can service.
- A second set of commitments. Card limits, HELP debt and loans of both applicants all count.
- A larger living-expense benchmark. A couple costs more to run than a single, though not double.
- Both credit files. A problem on one file can affect the whole application.
Dependants change the sum
Children raise the expense benchmark lenders apply, which lowers what you can borrow on the same income. Each additional child often adds less than the one before, and lenders differ in how much they add.
When one income is less certain
Casual work, self-employment, commission, or a partner about to take parental leave can all be shaded or need extra history. If one partner's income is uncertain, ask how each lender treats it, since this is one of the areas where lenders differ the most.
Applying on one income instead
Applying on one income only can be simpler if the other partner has debts or an untidy credit file, but the loan is then tested on that one income alone. Run both scenarios in the calculator before you decide.
Before you apply
- Gather payslips, card limits and loan statements for each applicant.
- Check both credit files for errors.
- Compare a joint result and a single-income result across several lenders.
- Talk to a broker about how each lender treats your particular mix of incomes.
See also credit card limits and HECS/HELP debt, which both count for each applicant.
How a broker helps, at no cost to you
- Finds the right lender. Compares lenders across their panel to find which will lend you the most, including those taking part in the 5% Deposit Scheme and Help to Buy.
- Handles the scheme. Checks your eligibility and the price cap, and applies for your scheme place through the lender.
- Gets you ready to bid. Sorts the paperwork and a pre-approval before you make an offer.
Who pays? Most mortgage brokers charge you nothing. The lender you choose pays the broker a commission when your loan settles. By law a broker must act in your best interests, not the lender's. We may receive a referral fee from the broker; it does not change what you pay.
This page is general information only, not credit advice or a recommendation. Lender policies change; a licensed broker or lender can confirm what applies to you.