The cost of late payments: why you get paid last

On 30 September 2026 the Reserve Bank lifted the cash rate to 4.60%, another 25 basis points on top of 4.35%. If your business carries an overdraft, equipment finance or a line of credit, you felt that one. If you also carry a large accounts receivable ledger, you felt something else, and it is worth naming properly.

Every unpaid invoice is credit. If a customer owes you $100,000, you have effectively lent them $100,000. The only real difference between your loan and their bank's is that the bank's costs them money every single day, and yours costs them nothing at all.

Why free credit gets repaid last

Human nature takes the path of least resistance. When cash gets tight, people pay whatever hurts the most first. So if one creditor is charging interest, adding fees and following a schedule, while another is sitting patiently on an invoice, the order has already been decided for you. Your $100,000 can sit there for 30, 60 or 90 days while you quietly finance somebody else's business at zero per cent.

This is not really an argument about 4.60%. It is true at any rate. Whenever money costs something, the debt that costs nothing goes to the back of the queue. A rate rise simply widens the gap between the creditor who charges and the creditor who waits.

Your accounts receivable is a loan you never approved

Accounts receivable is just the money your customers owe you for work you have already delivered. On your balance sheet it is an asset, and if the term is new to you there is a plain English guide to what accounts receivable actually is. In practice it behaves like a loan book that nobody ever wrote a credit policy for.

A lender would never hand over $100,000, wait three months and then ask how things are going. Before the money moved, they would want four answers:

• ✓Who exactly are we lending to, as a legal entity rather than a name over a door
• ✓What does the risk look like, and has this borrower paid on time before
• ✓How much total exposure do we have to this one name right now
• ✓When precisely do we get it back, and what happens if we do not

Most business owners cannot answer all four about their biggest debtor, and it is not carelessness. The information is scattered across an accounting system, an inbox and somebody's memory, and nothing pulls it together into a position you can actually look at.

What that free credit actually costs you

The cost of late payments is rarely a line item anywhere, which is exactly why it goes unmanaged. It is real money, and most of it can be worked out from figures you already have.

• ✓The interest on your own facility. If an overdraft is bridging a gap your customers created, you are paying your bank's rate, which sits above the cash rate, in order to lend your customers money for free.
• ✓The work you could not take on. Cash tied up in receivables is not available for stock, wages or a deposit on the next job.
• ✓The discounts you could not take. Paying your own suppliers early is often worth real money, and you cannot do it with money you have not been paid.
• ✓The hours. Chasing is skilled, uncomfortable work, so it almost always lands on your most senior people, or on you.
• ✓The compounding. The older an invoice gets, the harder the conversation becomes, the more chance the customer's own position has moved against you, and the more likely it ends up a debt collection problem rather than an invoicing one.

None of that appears on a profit and loss statement under a heading that tells you what happened. It turns up as a tight month.

Can you charge interest on overdue invoices in Australia?

Usually yes, but only if you set it up before the work started. Charging interest on overdue invoices in Australia depends on the agreement between you and your customer, so the right to do it needs to sit in the payment terms they accepted rather than appear for the first time on a reminder. Plenty of businesses already have the clause in their terms and have never once used it.

If your terms are silent on it, adding a late payment clause to the next version is a cheap change with a long tail. Worth running past your accountant or solicitor so it is worded properly for your business, because this is general information rather than legal or financial advice.

And here is the honest part. The value of that clause is usually not the interest you collect, because most businesses never invoice it. The value is that it removes the reason you are last in the queue. A payment term with a consequence behind it carries weight. A payment term with nothing behind it is a preference.

Underwrite the customer before you extend the credit

• ✓Know the legal entity. The company name and ABN, not the trading name. Getting this wrong is what undoes recovery later, when it matters most.
• ✓Set payment terms you actually mean, and shorter terms for a customer you are less sure about.
• ✓Ask new accounts to apply for credit rather than simply receive it. A one page credit application and a trade reference cost you nothing and change the tone of every conversation that follows.
• ✓Cap your exposure. One customer holding a large share of your overdue book is a single point of failure, however much you like them.
• ✓Decide the consequences in advance. What happens at 7 days, at 30, at 45, and who decides it.

On that last point, the sequence most Australian businesses can comfortably defend is a friendly payment reminder about a week after the due date, a firmer one at two weeks, a final notice at thirty days and a formal Letter of Demand at around forty five. Our payment reminder templates are on the page to copy, there are samples of a letter for outstanding payment for the firmer stages, and a full guide to writing a Letter of Demand in Australia for the step at the end.

Then monitor it the way a lender would

Lenders do not rely on goodwill. They monitor, on a schedule, whether or not anybody feels like doing it that week. The receivables version is not complicated, and it comes down to seeing three things without having to go hunting for them.

Ageing, first. An aged trial balance, which your accounting system might call an aged receivables report, tells you how old your money is and what share of it has drifted past 60 and 90 days. Then movement: finance teams track days sales outstanding for exactly this reason, because the question is whether money is coming back faster or slower than last month. And then the people. A customer who used to pay at 20 days and now pays at 50 is telling you something well before they tell you anything.

That is the job Mona was built for, and it is why she is a collections process rather than a reminder setting. Every morning, without anybody deciding to do it:

• ✓Every overdue invoice on your ledger is chased, so nothing is missed because the week got busy
• ✓Letters go out by customer rather than by invoice, so somebody owing four invoices gets one professional letter with one total
• ✓The sequence escalates properly: friendly, then firm, then final notice, then a formal Letter of Demand
• ✓Exposure is flagged, when a single debtor holds a quarter or more of everything you are owed
• ✓Repeat late payers are flagged, three separate overdue runs from the same customer inside six months
• ✓So are the customers who only ever pay under pressure, where the last two runs both needed a final notice
• ✓You are shown how much of what you were owed at the start of the month is still sitting there unpaid
• ✓Anything paid drops out of the chase on its own, so nobody is chased for money they have already sent

The detail of how that runs is on the accounts receivable software page, with the pricing in plain view. If you would rather read about tone than mechanics, start with chasing overdue invoices without losing the customer.

The point was never the rate

Rates will move again, in both directions, and the structure underneath will not change at all. You are a lender. You have always been a lender. You are simply an unusually patient one, who never charged for the service, never asked for security and never set a repayment date you were willing to enforce.

Your accounts receivable ledger is a credit book. Treat it like credit and it starts behaving like credit. Maybe it is time to take yours as seriously as the lenders take theirs.