How Mascot Business Owners Can Stress‑Test a Home Loan Properly

If you own a home in Mascot and run a business, you should stress‑test your mortgage by assuming a 30–50% drop in your business drawings and a 2–3% rise in interest rates, then checking whether you can still cover repayments and basic living costs with some surplus left.

That’s effectively what prudent lenders and APRA’s 3% buffer do, but you need to run your own numbers regularly because your business risk changes much faster than bank policy.

Run your own home loan stress test before business conditions turn against you.

Step 1: Define your worst‑case Mascot scenario

For most Mascot business owners, three realistic shock scenarios cover 90% of risk:

1. Income shock only – big client loss, slow quarter, illness.
2. Rate shock only – RBA hikes, lender repricing.
3. Double shock – revenue fall and higher rates.

Roy Morgan’s 2026 data shows over 28% of mortgage holders are ‘At Risk’ of stress as rates rise, with employment status a key driver. If you’re self‑employed, you sit closer to the edge by default.

Use these working assumptions (aligned with our other stress‑testing guides):

• Income drop: 30–50% in business drawings.
• Rate rise: +2–3% above today’s rate.
• Duration: at least 6–12 months of pain.

If your numbers only work for three months, that’s not a real buffer.

Step 2: Run the actual numbers on your Mascot home loan

Let’s use a simple example to show the maths.

• Mascot home value: $1.2m
• Loan: $800k, 30‑year term
• Current rate (variable): 6.0% p.a.

2.1 Current repayment

At 6.0% over 30 years, principal + interest repayments are roughly $4,800/month.

Add:

• Rates, strata, insurance, utilities, essentials: say $3,700/month

Total core outgoings: $8,500/month.

If combined after‑tax household income is $13,000/month, you currently have about $4,500/month surplus.

2.2 Income shock only

Assume a 40% drop in drawings for 9–12 months.

• New household income: $7,800/month (60% of $13,000)
• Outgoings still: $8,500/month

You’re now $700/month short. You need either buffers, quick cost cuts, or both.

2.3 Rate shock only

Keep income at $13,000/month, lift the rate by 3%.

• Rate: 9.0% (illustrative, not a prediction)
• New repayment: roughly $6,500/month
• Other costs: $3,700/month

Total outgoings: $10,200/month.

Surplus shrinks from $4,500 to $2,800/month. Uncomfortable, but manageable if buffers exist.

2.4 Double shock (what APRA really worries about)

Now combine the two – 40% income drop and 3% rate rise.

• Income: $7,800/month
• Outgoings: $10,200/month

Cash shortfall: $2,400/month. Over 12 months, that’s $28,800 you must fund from buffers, extra income or heavy cost cuts.

If you don’t like that number, your structure and buffers need work.

For a deeper buffer framework (including HEM and living cost checks), see How to Protect Your Home Loan When Your Income Jumps Around.