Sole trader? How business facilities can quietly sink your home loan

As a sole trader, your working capital facility – overdraft, line of credit, business credit card – doesn’t sit in a separate universe to your home loan. When you apply for a mortgage, most lenders treat these facilities as ongoing debts, usually based on the full limit, not just what you’ve used. That can materially cut your borrowing power under APRA’s 3% serviceability buffer and, in some cases, spook a credit assessor.

This guide walks through how those facilities actually show up in your home loan application, how different banks read your statements, and what you can tidy up this quarter so your business stays funded without quietly killing your next property move.

Lenders trace your working capital facilities directly into their home loan assessment for sole traders.

1. Quick answer: how working capital hits a sole trader’s mortgage

For most sole traders, lenders treat working capital facilities as if they were personal debts, even if the facility is in your ABN name.

In practice, that means:

1. Limits count, not just balances. A $50,000 overdraft is usually assessed as a $50,000 revolving debt, even if you’re only using $5,000.
2. Buffered repayments are assumed. Banks apply a notional repayment and then add APRA’s 3% buffer to the interest rate to test your cashflow.
3. Messy usage is a red flag. Using facilities for personal spending, tax debt or to plug chronic losses can trigger shading of your income or an outright decline.

The good news: with 3–12 months’ planning, you can usually reshape those facilities so they’re both business‑fit and ‘bank‑ready’. For background on why this matters so much, see also Will Your Working Capital Facility Kill Your Home Loan Borrowing Power?.

2. What counts as a “working capital facility” for a sole trader?

2.1 Common facilities lenders look for

When a credit assessor picks up your file, they scan for any recurring or revolving business debt, including:

• Business overdrafts attached to your trading account
• Business lines of credit
• Business credit cards
• Trade finance or debtor finance limits
• Short‑term business loans from banks and fintechs
• Buy‑now‑pay‑later style business accounts

If you’re a sole trader, the lines between “you” and the business are blurry in legal terms. The bank knows this, so they treat most of this debt as personal exposure, not fully quarantined in a separate legal entity.

2.2 Formal facilities vs informal working capital

Lenders distinguish between:

• Formal facilities – overdrafts, business loans and limits documented in credit contracts; and
• Informal working capital – using home loan redraw, personal credit cards or your personal overdraft to cover BAS, wages or suppliers.

Both can affect your home loan:

• Formal facilities will be listed as liabilities and assessed with notional repayments.
• Informal working capital often shows up in your bank statements, revealing that your home and personal facilities are effectively acting as an overdraft for the business.

Across multiple articles in our hub, we’ve seen that using home loan redraw or personal offset as recurring business working capital creates mixed‑purpose debt and concentrates business risk on the family home. It also complicates tax deductibility and tracing, which is the opposite of what you want when a bank’s credit team and your accountant both start asking questions.

For a deeper primer on structures and safe limits, see Working Capital Basics: Structures, Costs And Safe Limits For SMEs.

3. How lenders actually assess your facilities

3.1 The “limit vs balance” trap

Most clients assume that if they’re not using much of their overdraft, it won’t hurt their application. Unfortunately, most lenders go the other way: they assess the full limit.

Typical rules of thumb (illustrative only):

• Overdrafts/lines of credit: assessed as if 3%–4% of the limit per month is payable
• Business credit cards: 3%–4% of the limit per month
• Term business loans: based on actual repayments, but with a higher stress‑test rate

So a $50,000 overdraft with a $5,000 balance might still be treated roughly the same way as a $50,000 credit card.

3.2 Worked example: impact on borrowing power

Assume:

• You’re a sole trader consultant
• Net taxable income: $140,000 (after adding back interest and some one‑off expenses)
• Personal living expenses (HEM‑like benchmark): $4,000/month
• No other personal debts
• Seeking a 30‑year P&I owner‑occupier loan at a 6.5% actual rate, assessed at 9.5% after buffer

Now compare two scenarios.

Scenario A: No working capital facility

The lender might be comfortable with a total monthly mortgage repayment of around $5,500–$6,000 based on their serviceability calculator.

This could translate to borrowing roughly $900,000–$950,000 (illustrative only; each bank’s calculator differs).

Scenario B: $50,000 overdraft limit

The bank assesses the overdraft as a revolving facility needing, say, 3.8% of the limit per month.

• Assessed monthly commitment: 3.8% × $50,000 = $1,900/month

That $1,900 is treated exactly like a car loan or big credit card bill.

Result:

• The maximum comfortable mortgage repayment might fall from, say, $5,800 to $3,900/month.
• That could shrink borrowing capacity from around $900,000–$950,000 down to roughly $600,000–$650,000.

Nothing changed in your actual cashflow – you still barely use the overdraft – but the potential to draw it matters to the bank.

3.3 Comparison: different facility types and how they show up

*Illustrative only. Each lender applies its own credit policy.

You’ll notice that short‑term, high‑repayment facilities are particularly damaging. This is why extending business loan terms can sometimes improve home loan serviceability, as explored in How Longer Business Loan Terms Can Protect Your Next Home Loan.

Different working capital structures show up very differently in home loan calculators.