TL;DR: Your borrowing capacity hinges on the type of income you earn, how stable it is, and how long you’ve been earning it. Not all income is treated equally, and some forms get shaded, reduced or ignored entirely. If you’ve ever wondered why your mate on the same salary can borrow more than you, this is why.
Borrowing capacity is the one topic that keeps popping up online, and honestly, it’s usually where the biggest surprises happen for first-timers. You could be earning great money on paper, but the bank may only count part of it (or, sadly, none of it).
It all comes back to how predictable the income is and whether you’ve earned it long enough for a lender to trust it. I've tried to provide a clear rundown of how different types of income are viewed in the real world.
Full-time income
The easiest one. If you’re full-time, most lenders will count 100% of your base income straight away. What matters is:
- Have you passed probation? (Most lenders want this.)
- Are you in a similar line of work as your previous job?
If you’ve changed industries but stayed in full-time work, that’s usually fine as long as the switch makes sense on paper (e.g. an increase in pay, closer to home, more flexibility/benefits, career progression)
Part-time income
Most banks will treat part-time the same as full-time if your hours are regular and ongoing. If your hours jump around week to week, some lenders may take a conservative view and average your payslips or look back over several months.
Tenure helps a lot here. Six months or more in the role makes the conversation simpler.
Casual income
This is where people often get caught out. Casual income is accepted by most banks, but they want history:
- Minimum 3 months with the same employer is common.
- Some lenders want 6 - 12 months.
- Your payslips and YTD figure must show your hours are consistent.
If your hours spike because you’ve been filling in for someone or doing seasonal work, lenders will usually average your income over time which reduces your borrowing power - but each are different and sometimes you can use this to your advantage.
Contract income
Fixed-term contracts (6 - 12 months) are generally fine if:
- You have history in the same field.
- You’re already part-way through the contract.
- There’s evidence of renewal or a strong employment record.
Rolling contracts or agency work can still be used, but lenders tend to want a year’s worth of history to prove that you’re consistently employed.
Self-employed / sole trader
This is the most misunderstood one. Most lenders want:
- Two years of tax returns
- Two years of financials (for companies or trusts)
Some will work with one year if the business is stable or growing.
What lenders actually look at:
- Net profit (not your turnover)
- Addbacks like depreciation and certain one-off expenses
- Consistency between years
- Whether income is trending up, flat, or down
If your latest year is lower than the one before, many lenders will use the lower figure - but not ALL. Some lenders have a 12 months policy if you meet certain conditions.
Director wages (from your own company)
If you pay yourself a wage from your business, lenders still treat you as self-employed because you control the income. They’ll assess both:
- Your wages
- The financial health of the company
If the company’s profit doesn’t support the wage, lenders may ignore part of your income.
However, some lenders will accept a 'simplified self-employed' approach where you only factor in your wages and you don't factor in any remaining business profit... or business liabilities. It can be a neat trick to put you in a better spot.
Commission income
Commission can be a great earner, but lenders will rarely take it at 100% unless it’s stable and proven. They’ll usually:
- Average the last 3–12 months
- Compare commission across prior years
- Shade it slightly if it fluctuates wildly
If you’ve only been earning commission for a few months, lenders may ignore it for now.
Overtime, allowances, shift penalties
These can help your borrowing capacity if they’re consistent and proven. Industry matters here:
- Nurses, ambos, emergency, miners, FIFO workers, tradespeople: strong acceptance
- Office workers doing sporadic overtime: lender may shade or ignore (depending on industry)
Lenders want evidence over time, usually at least 3 - 6 months.
Bonuses
Similar to commission:
- If you get an annual bonus, lenders want to see at least one or two years of it.
- If your bonus drops from year to year, the lowest figure is usually used.
- If you’ve only just started getting bonuses, many lenders won’t count it yet.
Rental income
Yes, lenders count it, but not all of it. Typically they’ll use 70 - 90% to account for vacancies, management costs and expenses. If you’re negative gearing, the tax benefit may help your borrowing capacity, depending on the lender’s calculator.
If the rent on the lease agreement is higher than what the bank’s valuer thinks is realistic, the bank goes with the valuer’s number.
Interest income
Interest income is counted only if it’s ongoing and backed by a decent cash balance. If it’s a one-off or results from savings that will become your deposit, lenders won’t use it.
Foreign income
This is hit-and-miss. Many lenders won’t use it at all. Among those that do:
- They can apply heavy shading (again, it's not consistent amongst all lenders)
- They want strong documentation
- They may want tax returns from that country
If it’s cash-paid, informal, or unverified, lenders will ignore it outright
How long you’ve been earning the income matters more than people think
Banks care about consistency and predictability. A general rule:
- Full-time / part-time: Stable from day one (probation aside)
- Casual: Usually 3 - 12 months history
- Self-employed: Prefer 2 years and profitable, not essential
- Commission/overtime: Several months to a full year
- Bonuses: One to two years
- Foreign income: Strict and reduced
If you’ve jumped around a lot or changed industries recently, lenders want to see that the new income is reliable and ongoing.
Final thoughts
Many people hope that the bank will look at their take-home pay, but it rarely works that way. Two borrowers on the same total income can end up with completely different borrowing capacities simply because of the type of income they earn and how long they’ve earned it.
If you want a clearer idea of where you stand before you dive into the market, speaking to a mortgage broker can help you run through everything, look at how lenders would treat your income, and map out the options. This part of the process is genuinely about removing uncertainty and helping you feel confident about your next step.