Cash flow and customer concentration: Stress-test your largest account
Updated: 1 day ago
High customer concentration can turn one delayed payment into a business-wide cash shortage, even when the customer remains profitable and likely to pay.
A major account can provide steady work, efficient delivery and a valuable relationship. It can also determine whether the business has money for its next payroll. Those two realities deserve to be assessed together.
For Australian owners, the useful test is the cash effect of a delay, reduced order or dispute. This guide extends the 13-week cash flow forecast with a focused review of dependence on one customer.
The short answer
Measure dependence on customer receipts and margin as well as sales revenue.
Identify the operating payments that fall before the largest expected receipt.
Test delayed payment, disputed invoices and lower future orders separately.
Agree practical actions before a late receipt becomes an urgent funding request.
What does customer concentration mean for cash?
Revenue concentration describes the share of sales generated by one customer or a small group. Cash concentration asks a different question: how much of the money needed for upcoming obligations depends on a particular receipt arriving on time?
A customer contributing 20% of annual revenue might account for most of next week’s expected collections. Conversely, a larger annual account that pays frequent small invoices may create a different timing exposure. Review the pattern rather than applying a universal acceptable percentage.
Also distinguish sales from contribution to costs. A high-volume account may consume substantial materials, labour or service time. Losing its revenue does not mean all associated costs disappear immediately, especially where staff, leases or supplier orders are already committed.
The profit versus cash flow guide explains why earnings do not establish the timing of available money. Apply that distinction to each major customer, including the work completed but not yet approved for billing.
Map the actual collection pathway
Identify who receives invoices, who approves them and which payment run will include them. Record missing purchase orders, timesheets or delivery evidence. An apparently overdue account can have an administrative problem that needs a specific document rather than another generic reminder.
The government’s payment terms guidance supports clear expectations about payment. For the concentration test, use the agreement alongside collection history and current information. An invoice due date is an assumption until the customer’s process and any exceptions are understood.
Group connected customers where appropriate. Separate trading names can belong to the same corporate group or share an approval team. A disruption to that group could affect several balances at once, even if the sales report lists them as different accounts.
Keep relationship information factual. A friendly assurance that payment is “being processed” is useful context, but it is not cleared cash. Record what has been confirmed, by whom and on what date.
A worked example: A two-week delay changes the result
Consider a hypothetical business with $18,000 of usable opening cash. Over the next fortnight it expects $52,000 from its largest customer and $16,000 from other customers. Assume wages, suppliers, rent and existing payments total $61,000 over that period.
If all receipts arrive before the relevant payments, the closing position is $25,000. That broad total looks comfortable. The sequence still needs testing, because some payments may occur before the large receipt even under the base case.
Now move the $52,000 receipt back by two weeks. Without other changes, the fortnight’s position becomes negative $27,000. The customer has not necessarily failed and the invoice may still be collectible. The business nevertheless needs a response to the intervening cash gap.
These original assumptions illustrate timing, not a lending recommendation. Add the actual dates, funding charges and repayment obligations before deciding how much headroom is necessary. Test whether the response simply shifts the shortfall to the following fortnight.
Run three different scenarios
First, test a timing delay while keeping the expected invoice amount unchanged. This identifies how long existing cash and confirmed available funding can support the business. State a reason for the delay assumption rather than selecting a convenient number of days.
Second, test a disputed or partly withheld payment. Separate the amount the customer accepts from the amount requiring resolution. Do not forecast the entire invoice as a routine receipt when there is evidence of an unresolved issue.
Third, test reduced future orders. This affects both receipts and the costs the business can genuinely avoid. A cancelled order may leave stock, staff capacity or subcontractor commitments that cannot be unwound immediately.
The government’s cash flow statement guidance provides a reference for documenting forecasts. Keep each scenario separate so management can see whether the issue is timing, collectability or a change in the business’s revenue base.
Which management actions are realistic?
Start with actions that address the cause. Resolve invoice defects, confirm approval contacts and discuss a practical collection schedule. For future work, consider whether agreed deposits, shorter billing intervals or different milestones would reduce exposure.
Review credit limits and escalation responsibilities. The person managing the relationship should know when finance needs to review further supply. A business should not continue increasing exposure merely because stopping to discuss payment feels uncomfortable.
The cash flow improvement guide considers operational responses before borrowing. Check contractual obligations before suspending work, changing terms or withholding delivery. Legal advice may be necessary, and a payment dispute should not be treated as a simple sales decision.
Diversifying customers can reduce future dependence, but it is rarely an immediate cash remedy. Winning and servicing new accounts may require further spending before the first receipt. Include those costs rather than assuming diversification produces instant liquidity.
What does the test mean for finance?
An unused limit may provide contingency capacity only while the facility remains available under its agreement. Confirm drawdown conditions, review dates and the effect of existing use. A second facility can also introduce another repayment before the major customer pays.
The finance structure comparison explains scheduled and revolving arrangements. For receivables-based funding, investigate whether customer concentration or invoice exclusions affect availability. A headline limit should not be treated as cash accessible against every debtor balance.
The working capital needs guide helps connect the scenario to the overall operating requirement. Give your finance broker a clear explanation of the customer dependency and the source expected to repay the proposed finance.
If the test shows an inability to meet obligations without repeated new borrowing, seek qualified help early. ASIC’s financial difficulty guidance is relevant where company cash pressure is becoming persistent. A concentration analysis should prompt action rather than provide reassurance through an optimistic receipt date.
A useful review checklist
What share of upcoming receipts depends on the largest customer or connected group?
Which documents or approvals stand between completed work and payment?
What happens to the lowest cash balance under each scenario?
Which costs can management genuinely change, and how quickly?
Who is responsible for discussing terms, collecting evidence and escalating the issue?
Frequently asked questions
Is a major customer always a problem?
No. A large relationship can be commercially valuable. The purpose of the test is to understand dependency and prepare for plausible disruption, not assume the customer will fail.
Is there one safe concentration percentage?
No universal figure suits every business or facility. Timing, margin, contractual commitments and the rest of the customer base affect the practical risk.
Can a reliable customer still create a cash gap?
Yes. Reliable eventual payment does not remove the need to fund wages and suppliers before collection. Even an administrative delay can move cash past an important payment date.
Does invoice finance remove customer risk?
Do not assume so. Eligibility, concentration limits, recourse, disputes and any protection depend on the agreement. Review the specific terms and remaining exposure.
Review the dependency before it becomes urgent
Keep a documented base case and a realistic delayed-receipt case. Agree the first action, responsible person and review date with your management team, then use the results in discussions with your accountant and finance broker.
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General information only. This article does not constitute financial, credit, legal, tax, accounting, compliance or valuation advice. Finance is subject to lender approval, eligibility criteria, terms, fees and conditions. Consider obtaining independent professional advice for your circumstances before acting.
