Delora

Preparing financially

How lenders actually calculate what you can borrow

Income shading, the expense benchmark, why credit limits (not balances) count, and the serviceability buffer applied on top of all three.

Jurisdiction: Australia-wide·Sources last verified: 29 Jul 2026·Written by: Delora editorial team·Last reviewed: 2026-08-04·Change history
Key points
  • Variable income (overtime, bonuses, rental income) is commonly 'shaded' — discounted, not counted in full.
  • Lenders compare your declared expenses against a standardised benchmark and use whichever is higher.
  • Credit card and BNPL limits count toward your assessment, not just what you currently owe.
  • The serviceability buffer is applied on top of all of the above, not instead of it.

Income: not every dollar counts the same

Lenders commonly apply "shading" — discounting a percentage of income types they consider less reliable, such as overtime, bonuses, casual shifts, or rental income from an investment property — rather than counting them in full. Base salary is typically counted at 100%; more variable income types are often shaded, sometimes substantially, and the exact discount varies by lender.

Expenses: the benchmark vs. your actual spending

Lenders are required to assess your actual declared expenses, but commonly compare them against a standardised expense benchmark — the Household Expenditure Measure (HEM), developed by the Melbourne Institute of Applied Economics — and use whichever figure is higher as a floor, meaning an unusually frugal household may still be assessed against a higher benchmark figure. This is a real reason two households with identical income can be assessed differently.

Debts: limits, not balances

For credit cards and similar revolving credit, lenders commonly assess serviceability against the credit limit, not your current balance — a $20,000 limit card you rarely use can still reduce your borrowing capacity as though it were close to fully drawn. Closing or reducing limits on cards you don't need before applying is a genuine, actionable step (see existing-debt guide).

The buffer, applied on top of all of this

After shading income, applying the expense benchmark, and counting debt limits, lenders then assess your ability to repay at a rate at least 3 percentage points above the loan's actual rate (Australian Prudential Regulation Authority, verified 29 Jul 2026) — see the safe-budget guide for what this buffer is actually for.

Common mistake: estimating borrowing capacity from gross income alone with an online rule of thumb, without accounting for income shading, the expense benchmark, or existing credit limits — often producing a figure well above what a real application would return.

Practical checklist

Before estimating your own borrowing capacity

  • List which parts of your income are base salary vs. variable (overtime, bonus, rental)
  • Check the credit limit (not balance) on every card and BNPL account you hold
  • Consider closing or reducing limits on cards you don't need before applying
  • Treat any online borrowing-capacity estimate as a rough starting point, not a real assessment

Questions for a professional

  • How is my variable income being treated in this assessment?
  • What expense benchmark are you using, and how does it compare with my actual spending?
  • Would reducing my credit card limits meaningfully change my borrowing capacity?

Official resources

Important limitations: This describes common lending practice, not any specific lender's policy — exact shading percentages, benchmarks and treatment of debts vary by lender and are not published as open data.

Sources and methodology

Figures on this page are drawn from Delora's local knowledge graph, refreshed from these primary sources and checked for changes on a regular schedule. If a figure here looks out of date, the official source above is always the authority — please let us know.

Evidence record
Written by
Delora editorial team
Jurisdiction
Australia-wide
Content type
Guide (general education, not financial advice)
Last reviewed
2026-08-04
Sources
See "Sources and methodology" above for cited sources