Which Customers Really Make Your Australian Business Money?

By Sonja Pfitz

The customers that make your business the most money are not always the ones that buy the most, because profitability depends on what it costs to win, service, deliver and wait for payment from each customer. Most business owners can name their five biggest customers by revenue straight away, but ask which five are the most profitable and the conversation often changes. A customer can generate impressive turnover while quietly consuming margin, staff time and working capital.

What Makes One Customer More Profitable Than Another?

Two customers can each spend $500,000 a year and deliver very different financial outcomes. One may order predictably, accept standard pricing, receive consolidated deliveries and pay within agreed terms, while the other negotiates discounts, places urgent orders, requires express freight, changes specifications regularly and pays late. Both produce the same sales number, yet the second leaves the business with far less to show for it, which is why turnover alone cannot measure the quality of a customer relationship.

Margin makes the gap clearer. Imagine a customer generating $1 million in annual sales at a 15 per cent gross margin, which produces $150,000 in gross profit before overhead. Now add the costs attached to that account, such as special freight, rebates, extra handling, more administration and longer payment terms. Compare that with a smaller customer spending $600,000 at a 30 per cent gross margin, who produces $180,000 in gross profit. Before any of those extra costs are counted, the smaller customer already contributes $30,000 more, although a ranking by revenue would suggest the opposite.

How Should You Measure Customer Profitability?

Start with the numbers you already have: annual revenue, gross profit, discounts, rebates, freight, returns and payment behaviour. Then look at what is harder to measure. How much time does your team spend managing the account, does the customer regularly create urgent work, do they require stock to be held specifically for them, and do they cause production interruptions or extra administration? Costs do not need to be allocated perfectly, because even a reasonable estimate can reveal a very different picture from the sales report, and your gross margin figures give you the starting point.

Payment behaviour also matters because it determines how long your business carries the cost of the sale. Assuming sales are spread evenly through the year, a customer buying $1 million a year and paying in 75 days leaves roughly $205,000 of your money outstanding on average, compared with roughly $38,000 if they pay in 14 days. You may already have paid suppliers, staff and operating costs while you wait, so a slow payer costs more than the same sale to a prompt one. That does not automatically make a slow-paying customer unprofitable, but it belongs in the calculation, and the credit side is covered in Should Australian Businesses Still Offer 30-Day Terms?

Why Can Your Largest Customer Be Your Biggest Risk?

Large customers often receive favourable terms, such as lower prices, extended payment periods or priority service, and that is frequently justified because volume has value. There is a point where the relationship can become commercially unbalanced. A customer may represent 25 per cent of revenue and an even larger share of your debtors, while also holding significant negotiating power and creating operational dependency. If that customer reduces orders, leaves or runs into financial difficulty, the effect on your business can be serious. Large customers can be excellent for a business, and the aim is to understand their value properly rather than assume it.

What Should You Do With an Unprofitable Customer?

The answer is not automatically to stop dealing with them, because the relationship can often be improved. Pricing may need to change, freight may need to be charged differently, minimum order quantities may help or payment terms may need to be shortened, and small changes like these can turn an unattractive account into a profitable one. If nothing changes and the account keeps absorbing resources without a reasonable return, walking away may eventually make sense, provided the decision rests on facts rather than frustration.

A difficult customer can still be worth keeping. They may provide access to a new market, use spare capacity or open up opportunities that a single year's figures do not show. Those benefits are legitimate as long as they are acknowledged clearly, because the real danger is when everyone in the business knows an account is demanding but nobody knows whether it makes money.

When Should You Review Customer Profitability?

A review is useful whenever margins are under pressure or the business feels busier without becoming more profitable. It is also worth doing before renewing a major contract, agreeing to a larger discount or allocating additional staff to a particular account, because those are the moments when the real economics of the relationship matter. If you are about to invest more resources in servicing a customer, you should know what that customer already contributes.

The need grows when costs are rising. While margins are healthy, inefficient customer arrangements can stay hidden because there is enough profit elsewhere to absorb them, but as costs climb the weak points become obvious, and a small number of customers often turn out to consume a disproportionate share of time and money. Improving profitability does not always require finding more customers, as More Sales Won't Fix a Bad Margin explains, and it can start with understanding the ones you already have.

Revenue is a useful way to rank customers, but a better view looks at revenue alongside gross profit, margin, payment behaviour and service requirements. Your biggest customer may still be your best customer, and the only way to know is to check rather than assume.

I have spent more than 30 years in finance and business. If you would like help working out which of your customers contribute most to profit, and what their payment terms cost your cashflow, contact Pfitz Financial or book a free confidential discussion.