Most business owners read the headline terms of a loan and skip the default clause. That is understandable. Nobody signs a loan expecting to miss it. But default interest on a business loan is where short-term funding gets expensive, and it rarely starts with a dramatic collapse. It starts with a settlement that slips a week, a customer who pays late, or a term that ends the day before the refinance lands.
This guide puts the clause into dollars, explains what a court will and won’t do about it, and shows the checks worth making before you sign. We don’t quote rates here, because pricing is individual, but the mechanics are the same on almost every deal.
What actually triggers default interest?
Three things, in roughly this order of frequency:
- A missed or late repayment. The obvious one. Many contracts have a short grace period, some have none.
- Reaching the end date unpaid. On a short-term property loan this is the big one. If the term is six or twelve months and the refinance or sale hasn’t settled by the final day, you are in default on day one after it.
- Breaching another promise. Letting insurance lapse, falling behind on council rates, a second charge appearing on the title, or a statement you gave the lender turning out to be wrong. Some of these can trigger default even if every repayment is on time.
That third category surprises people. Read the “events of default” list in the contract itself. It is usually longer than the lender’s summary suggests.
How does default interest turn into dollars?
Three features decide the cost, and none involves a headline number:
- What it applies to. Most clauses apply the default rate to the full outstanding balance, not the late instalment.
- Whether it compounds. If unpaid interest is added to the balance and attracts further interest, the daily cost grows over time.
- What sits on top. Default fees, the lender’s legal costs, enforcement costs and sometimes re-documentation charges.
Illustrative example: Business A borrows $400,000 over twelve months against a commercial property, with a planned bank refinance as the exit. The contract’s default clause, once translated by the lender into a payout figure, adds $180 a day to the balance after the end date. The bank refinance slips three weeks because of a documentation query. That is roughly $3,800 in extra interest, plus a $1,500 default fee and $2,500 of the lender’s legal costs for chasing the file. The total is about $7,800 for a three-week delay, before anything else goes wrong.
Those numbers are made up for illustration, but the shape is real: a modest daily figure, a fixed fee and legal time add up fast, and the bill lands exactly when your cash is tightest.
| Cost layer | Typical behaviour | What to ask |
|---|---|---|
| Extra interest | Runs on the whole balance from the default date | “What is the extra dollar cost per day on my balance?” |
| Compounding | Interest added to balance, then charged on again | “Does default interest compound, and how often?” |
| Default fee | Often a flat amount | “Is there a default or reinstatement fee?” |
| Legal costs | Lender’s solicitors, sometimes on a full indemnity basis | “Which legal costs am I liable for?” |
| Enforcement | Costs of taking possession or selling security | “What is recoverable if you act on the security?” |
Can a court cut default interest down?
Sometimes. Australian law doesn’t let a lender enforce a term that works as a penalty. In plain words, a default rate has to protect the lender’s legitimate interest, such as extra risk and admin cost, rather than punish you. Whether it does is judged case by case.
Two recent decisions show how uneven the outcomes are:
- In Crescent Capital v Chanine [2026] NSWSC 371, the court found a default interest provision in a non-bank construction loan was not a penalty. Law-firm commentary on the case notes that a substantial default rate triggered by many events, regardless of severity, is more open to challenge than a narrower clause.
- In Blackbird First Mortgage v Cam Engineering [2026] NSWSC 876 (July 2026), the NSW Supreme Court held that a default rate that doubled the standard rate was an unenforceable penalty. The lender led almost no evidence to justify the uplift, and its default costs were already covered by separate indemnities. The court struck out only the uplift. The borrowers still owed interest at the standard rate from the date of default, and about $145,000 of fees was disallowed because the lender hadn’t produced the certificate the mortgage required.
The lesson is not “default interest is unenforceable”. It is that a lender’s paperwork and justification matter, and that a challenge is slow, costly and uncertain. It is a defence of last resort, not a plan.
Does unfair contract terms law help a small business?
Often, yes, for standard-form contracts. The unfair contract terms regime was strengthened from November 2023: it covers small business contracts where at least one party has fewer than 100 employees or turnover under $10 million, and proposing or relying on an unfair term can now attract civil penalties, not just a declaration that the term is void. The ACCC explains the test, and ASIC has taken action against a major payments company over a term in its small business contracts.
Two limits matter. The regime applies to standard-form contracts, and many private property loans are individually negotiated, so don’t assume cover. And it may not reach terms that define the main subject of the contract or the upfront price. Treat it as a possible argument, not a safety net.
When does default usually start on a short-term property loan?
Almost always at the exit. Short-term funding is built around a refinance or a sale, and both can slip for reasons outside your control: a bank credit team behind on files, a buyer’s finance delayed, a registry or settlement date moved. Our guide on what slows down a business loan approval covers the usual culprits, and the exit strategy guide shows how to build in slack.
A practical rule: treat the contract end date as the day by which the exit must already be unconditional, not the day you start settling. Add three to four weeks of buffer.
What should I check before I sign?
Ask these in writing and keep the answers:
- What is the default rate or default cost, in dollars per day on my actual balance?
- What exactly counts as a default? Can I see the full list?
- Is there a grace period for a late payment or the end date?
- Does default interest compound, and does it apply to the whole balance?
- What are the default fees and which legal costs would I pay?
- Can the term be extended, and what would that cost compared with default?
- If the loan is a caveat loan or second mortgage, what happens to the security on default?
If the lender can’t answer in dollars, that is information in itself. A caveat loan or short-term business loan can be a sensible tool when the exit is realistic. The question is whether the paperwork leaves you room if it isn’t. Not sure how a particular term reads? You can check your options and talk it through with a person who reads these contracts every day.
What if I’m already late, or about to be?
Move early. In order:
- Call the lender before the due date. Lenders handle a request for time at that stage very differently from a missed payment.
- Bring a dated plan. A signed contract of sale, a bank’s conditional approval or a debtor’s payment advice is worth more than a promise.
- Ask for any extension in writing and get the cost in dollars.
- Price the alternatives. Refinancing into a fresh facility, even one with establishment costs, can be cheaper than weeks of default charges. See business loan interest rates and fees for how fees are structured.
- Don’t ignore notices. A default notice starts a clock. Respond within it.
Ready to see where you stand?
If a term is coming to an end, or you’re signing something with a default clause you don’t fully trust, the best time to talk is before the date, not after it. Our team can look at your situation, whether that’s a property-backed loan that needs a realistic exit or an unsecured option for a trading business, and talk you through what fits.
Enquiring takes about 60 seconds, and there is no credit check when you enquire, so asking won’t touch your credit score. We don’t send your details to a pile of lenders; a real person looks at your individual situation and calls you. Please fill the form in accurately, because the more precise it is, the more likely we are to match the right option first time.