Business Debts, Credit Cards and Car Loans: Protect Your Borrowing Power

If you run a business, have a couple of credit cards and a car loan, it can feel like buying a home is miles away.

The reality: you may be closer than you think. But you need to understand how every card limit, personal loan, car lease and business facility shows up in a lender’s calculator.

In this guide, we’ll unpack how those debts hit your borrowing power, then give you a one-week action plan to tidy things up before you apply.

In plain English: Australian lenders look at your income, subtract a standard living expense benchmark, then load in all your debts—personal and many business ones—at a higher test rate. Every $1 of monthly repayment they see is roughly $15–$20 less home loan they’re comfortable with. Reducing limits, closing unused facilities and structuring car and business finance properly can easily add $50,000–$200,000 to your borrowing capacity.

Understanding how each debt type shows up in a lender’s calculator is the first step.

1. How lenders actually calculate your borrowing power

1.1 The serviceability formula in plain English

When you apply for a home loan, the bank’s calculator (broadly) does this:

1. Adds up your gross income (salary, business income, rent, benefits).
2. Subtracts income tax to get net income.
3. Subtracts living expenses (your declared numbers, but cross‑checked against the Household Expenditure Measure – HEM).
4. Subtracts all existing debt repayments, including many business facilities.
5. Checks what’s left against the “stress-tested” repayment on the new home loan.

Most lenders in Australia currently add a 3% buffer above the actual interest rate to test affordability, in line with APRA guidance. So if your home loan rate is 6% p.a., they’ll test it at around 9% p.a. to make sure you can handle future rate rises.

If the leftover cash after steps 1–4 covers that higher test repayment with some margin, you pass. If not, they cut back how much they’re willing to lend.

1.2 Why limits matter more than balances on cards and overdrafts

With credit cards and many overdrafts, lenders don’t care much what you owe today. They care what you could owe.

Most will assume a monthly repayment of roughly 3% of the total limit, even if you clear it every month.

So a $20,000 card limit usually gets treated as a $600/month commitment. A $5,000 overdraft limit might be treated as $150/month, even if it’s at zero.

That $750/month total directly reduces the income available to service a home loan.

1.3 The self-employed twist: when business and personal blur

If you’re self‑employed, things get more complex:

• Lenders generally start from your taxable profit, not your pre‑deduction turnover.
• Aggressively minimising taxable income can significantly reduce borrowing capacity because the bank works from the lowest number in your financials and tax returns.
• In Australia, most lenders treat business facilities with a personal guarantee as personal commitments when assessing your home loan, even if repayments come from the business account (see also /insights/clean-up-credit-file-small-business-owner).

So a business overdraft, vehicle finance or equipment loan you “thought” was off your personal radar may be counted against you.

For a deeper dive on proving income without payslips, see /insights/self-employed-to-homeowner-without-payslip.

2. Credit cards and personal loans: small balances, big damage

2.1 How cards and personal loans are assessed

Most Australian lenders assess consumer debts roughly like this (policy varies by lender):

• Credit cards & personal overdrafts: 3% of the limit as a monthly repayment.
• Personal loans: the actual contractual monthly repayment (principal and interest).
• Buy Now Pay Later (BNPL): often treated as a small personal loan or as ongoing monthly commitments.

Even if you’re a “points hacker” who pays the card in full each month, a big limit still hurts your numbers.

2.2 Worked example: how $20k in cards can slash your capacity

Let’s use simple, rounded numbers and an indicative interest rate just to show the effect. (This is illustrative only, not a quote.)

Assume:

• Combined household gross income: $150,000 p.a.
• No kids, standard living expenses at HEM.
• No other debts.
• Target home loan on principal & interest over 30 years.

With no consumer debts, a typical lender might be comfortable around a $800,000 home loan (tested at a 3% higher rate).

Now add:

• Credit card limit: $20,000 → assessed at ~$600/month.
• Personal loan: $15,000 with repayments of ~$350/month.

Total extra monthly commitments: $950.

At today’s test rates, an extra $950/month could easily chop your borrowing power down by $120,000–$160,000+. Suddenly the same household may only qualify for $640,000–$680,000 instead of $800,000.

The message: those “manageable” debts are not neutral. They’re crowding out space in your borrowing capacity.

For first‑home buyers in tight markets like Sydney, that difference can be the gap between a unit further out and something close to where you actually work and live (see also /insights/navigating-sydney-first-home-buyer-market-2026).

2.3 What you can do this week

If you’re 3–12 months away from applying, quick wins include:

• Cut unused credit card limits. If you run $2,000/month through a card for points, you don’t need a $25,000 limit. Dropping to $5,000 can free up ~$600/month in the calculator.
• Close duplicate or legacy cards. Old fee‑charging cards you barely use are pure dead weight.
• Refinance high‑rate personal loans. If you can replace multiple small personal loans with a single lower‑rate facility (without extending the term too far), your assessed monthly repayments can drop.
• Clear small BNPLs and stop using them. Lenders are increasingly wary of BNPL. See /insights/bnpl-overdrafts-trade-accounts-hidden-debts for how these “hidden debts” are treated.

These are changes you can start this week that often show up in your bank statements and credit file within 1–3 months.

3. Car loans and vehicle finance: personal vs business

Most households have a car. For small business owners and tradies, that car (or ute, or van) is often partly business, partly personal. Lenders still need to put it somewhere in their calculator.

3.1 How personal car loans are treated

If the car loan is clearly in your personal name, lenders will:

• Use the actual monthly repayment (including any balloon component if payable during the term).
• Add this to your other commitments before testing your new home loan.

On a $40,000 five‑year car loan at an indicative 9% p.a., repayments might be about $830/month. That one loan alone can slice $100,000–$150,000 off your borrowing capacity, depending on your income and other expenses.

3.2 When “business” car finance still hits your personal capacity

Even when vehicle finance is in the business name, many lenders still treat the repayments as personal commitments for home loan purposes:

• You’re usually signing as a director or personal guarantor.
• The car is often used personally as well as for business.
• The lender wants to know you could service everything if the business had a bad year.

So that chattel mortgage or business lease on the work ute can still be treated as a monthly commitment in your personal serviceability.

This is particularly important if you’re planning to upgrade vehicles and buy a home in the same 12–24 months. The order and structure in which you do those can make a big difference.

3.3 Balloons, novated leases and cashflow traps

Balloon (or residual) payments and novated leases are often sold as a way to “keep repayments low”. Lenders see them a bit differently:

• Balloons reduce monthly repayments but increase total interest and create a lump‑sum risk at the end of the term.
• For serviceability, lenders typically count the monthly repayment during the term, and will also look at what happens when the balloon falls due.
• Novated leases usually only suit small business owners who pay themselves a regular PAYG salary. They’re less appropriate for sole traders living off irregular drawings.

If your lease expires or balloon is due shortly after your proposed home loan settlement, a conservative lender may model in a future refinance or payout, further tightening your borrowing power.

3.4 If you need a car and a home loan

If both are on the cards in the next year or two, consider:

• Delaying the car upgrade until after you buy if possible.
• Buying a slightly cheaper car with a smaller loan to reduce monthly commitments.
• Longer car loan term, but with extra repayments. This can keep the assessed minimum low while you aggressively pay it down.
• Structuring as genuine business finance where appropriate, with clear business use and clean separation of business and personal banking.

The right structure can be the difference between a lender saying “yes at your target price” or “yes, but you’ll need to drop your budget by $100,000”.

Vehicle finance, even in a business name, often affects your personal borrowing capacity.

4. Business debts and credit facilities: what counts, what hurts

For self‑employed borrowers, business debts are often the murkiest part of the picture.

4.1 Common business facilities and how they’re viewed

Typical facilities a lender will ask about include:

• Business overdrafts and lines of credit.
• Term loans for equipment or fit‑outs.
• Vehicle finance in the company or trading name.
• Trade finance or invoice finance arrangements.

If you’ve signed a personal guarantee, many lenders will:

• Treat the full monthly repayment as a commitment, or
• At minimum, shade your income (e.g. only take 70–80% of net profit) to allow for business debt servicing.

Well‑structured, income‑generating business finance is usually viewed more favourably than high‑interest personal debt, but it still reduces the income available for a home loan.

4.2 High-impact short-term credit and trade accounts

Short‑term credit such as BNPL, personal overdrafts and loose trade accounts usually has a higher negative impact on borrowing power than a similar‑sized, amortising business term loan.

Lenders worry about:

• The behavioural signal – constantly using short‑term credit suggests cashflow strain.
• Lack of clear end date – unlike a term loan, these can run on indefinitely.

Consistently overdue trade credit accounts can be read as quasi‑business debt and may spook underwriters, especially if bank statements show a pattern of juggling payments (see /insights/bnpl-overdrafts-trade-accounts-hidden-debts).

4.3 ATO debts and payment plans

Overdue tax returns or unmanaged ATO debt are big red flags. Lenders see them as a sign the business (and by extension, the individual) is under financial stress.

Often you’ll need to:

• Lodge all outstanding returns before a lender will even fully assess the application.
• Show a formal ATO payment plan that has been conducted well for several months, or
• Clear the ATO debt entirely, sometimes via consolidating into a home loan or separate refinance (this draws extra scrutiny; see /insights/demystifying-debt-consolidation-using-home-equity-wisely).

Sorting this out early is critical. Tax issues can derail an otherwise strong application at the last minute.

5. How much do these debts really reduce borrowing power?

Here’s an illustrative table showing how different debts might impact capacity for a typical household. Assumptions are simplified and for education only – real outcomes vary by lender and scenario.

*Indicative only. Actual impact depends on income, living expenses, tax, and lender policy.

A few patterns to notice:

• Limits hurt, not just balances. That unused $15,000 card “just in case” is quietly costing you.
• Shorter‑term loans have high monthly repayments, so they bite hard on borrowing power even if the rate is reasonable.
• Business loans with personal guarantees often show up in the same column as your personal car loan.

This is why part of smart home loan prep is reshaping your debts – not just making random extra repayments.

6. One-week action plan to tidy debts before you apply

You don’t have to fix everything overnight. But you can make meaningful progress in seven days.

6.1 Day 1–2: Audit every facility

List out, in a spreadsheet or notebook:

• All credit cards and limits.
• Personal loans and remaining terms.
• Car loans and leases.
• BNPL accounts, store cards, and personal overdrafts.
• Business overdrafts, vehicle finance, trade accounts and term loans (note which have personal guarantees).

Pull your credit reports from all three major bureaus and cross‑check. Our guide /insights/clean-up-credit-file-small-business-owner has a step‑by‑step process.

6.2 Day 3–4: Quick wins with big payoff

Focus first on changes that reduce assessed monthly commitments without blowing up your cashflow:

• Reduce excess credit card limits. Drop them to the lowest practical level.
• Close genuinely unused cards and BNPL accounts. This also reduces temptation to re‑spend.
• Pay off tiny, untidy debts. If you can clear a $1,000 BNPL or a $2,000 store card, do it and close it.
• Move recurring bills off BNPL and onto your bank account or debit card. Show lenders 3–6 months of clean conduct.

6.3 Day 5: Map medium-term changes (3–12 months)

Some levers take longer but can dramatically improve your position:

• Plan the order of big purchases. If you’re close to buying a home, consider delaying vehicle or equipment upgrades.
• Restructure personal loans where sensible. A refinance to a lower rate or longer term can reduce your assessed minimums.
• Tidy business cashflow. Reduce reliance on overdrafts and short‑term credit by tightening invoicing and expenses.

If you’re early in your business journey, /insights/start-up-to-homeowner-five-year-roadmap outlines how to line up business decisions with a future mortgage application.

6.4 Day 6–7: Decide if consolidation makes sense

Finally, consider whether bringing multiple debts together is worth it:

• Consolidating into a home loan or separate low‑rate facility can slash monthly repayments.
• But stretching short‑term debts over 25–30 years can increase total interest if you only pay the minimum.

Our guide /insights/demystifying-debt-consolidation-using-home-equity-wisely sets out when consolidation is smart, and when it just kicks the can down the road.

This is the point where tailored advice from a broker who understands both business and tax is worth its weight in gold.

A focused one-week clean-up can significantly improve your home loan options.

7. Strategy for self-employed and small business owners

7.1 Separate business and personal early

Mixing business and personal spending in one account makes it harder for lenders to see a stable income story.

Separating accounts early achieves three things:

• Makes it easier to prove income from business activity statements, financials and bank statements.
• Helps show business debts are genuinely tied to revenue‑generating assets.
• Reduces “noise” in your personal statements, which underwriters manually review.

This separation is one of the recurring themes in /insights/self-employed-to-homeowner-without-payslip.

7.2 Pay yourself in a lender-friendly way

Regular, predictable drawings or wages from the business over 12–18 months usually look better to lenders than ad hoc transfers.

Where possible:

• Set a consistent monthly “salary” or drawing that the business can comfortably support.
• Avoid large, irregular lump‑sum withdrawals that look like emergency cash grabs.
• Work with your accountant so your taxable income for at least the last two years reflects what you’ll need to borrow – not just the absolute lowest tax bill.

Lenders often average the last two years’ taxable income or take the lower year if there’s a big drop, so plan ahead.

7.3 Time your home loan around major business moves

If you’re planning to:

• Take on a large new business loan or lease,
• Upgrade multiple vehicles,
• Sign a big office or shop fit‑out contract, or
• Commit to an off‑the‑plan purchase that settles in 18–24 months,

build your home loan strategy around that timeline. For example:

• You might prioritise securing the home loan first, then add business debt once you’re in the property.
• Or restructure existing business finance into clearer, amortising loans before applying, so the lender isn’t spooked by constant overdraft usage.

A broker who lives in both the business‑finance and mortgage worlds can help map out the right order and structure.

8. When to get advice – and what to bring

If you’re within 12–18 months of wanting to buy, upgrade or refinance, it’s worth a conversation now, not three weeks before auction.

8.1 What a good broker will look at

A broker with both mortgage and business‑finance experience will:

• Recreate the bank’s serviceability calculation across several lenders.
• Model different scenarios: lower card limits, cleared car loan, consolidated personal debts, different ways of paying yourself.
• Flag any deal‑breakers early, such as overdue tax, messy credit files or short business trading history.

8.2 Documents and numbers to have ready

You’ll save time (and get better advice) if you can provide:

• 6–12 months of personal and business bank statements.
• Last 2 years of tax returns and financials (if self‑employed).
• A full list of all debts, limits, rates and remaining terms.
• Any ATO payment plans, lease agreements and business loan contracts.

From there, you can work backwards: what needs cleaning up, in what order, and on what timeline, to give you the best shot at the property you actually want.

Key takeaways

• Lenders test your home loan at a rate about 3% above today’s, so every dollar of existing monthly repayments sharply reduces borrowing power.
• Credit card and overdraft limits are often more damaging than the balance because banks assume a percentage of the limit as an ongoing commitment.
• Many “business” loans, especially vehicle finance and facilities with personal guarantees, are treated as personal commitments in home loan assessments.
• Quick wins this week include cutting card limits, closing unused facilities, clearing tiny debts and tidying BNPL and overdraft use.
• Self‑employed borrowers should focus on clean financials, regular drawings and early separation of business and personal banking to maximise borrowing capacity.

If you’d like a clear, numbers‑driven view of how your specific debts affect your borrowing power – and a practical plan to fix it – a broker who understands both tax and business finance can map it out with you.

General advice only.