Winning a major customer can be a huge step forward for a business. A large account can bring in steady revenue, help make operations more efficient, improve buying power with suppliers, and give the business greater credibility in its industry.
The challenge is that the same customer can become a concern when the owner eventually decides to sell. If too much of the business depends on one customer, or a small group of customers, buyers may see that as a risk. This is commonly referred to as customer concentration.
The issue is not simply how much revenue the customer generates today. Buyers will also think about what would happen if that customer reduced its orders, moved to a competitor, ran into financial trouble, or ended the relationship altogether. From the owner's perspective, a major customer may be one of the most valuable parts of the business. From the buyer's perspective, the question is often more cautious: how much of the business would be affected if that customer disappeared?
Business buyers are purchasing future earnings, not simply historical revenue.
If a business has generated $2 million of annual profit but a large proportion of that profit depends on one customer, the buyer needs to determine how sustainable those earnings really are.
A highly concentrated customer base can therefore influence:
Customer concentration does not automatically make a business unattractive. The quality, duration, profitability, and defensibility of the customer relationship are just as important as its size.
Customer concentration is not just about identifying the single biggest customer. Buyers will usually look at the wider customer mix to understand how dependent the business is on a relatively small number of accounts. For example, one business might have its largest customer contributing only 8 percent of revenue, with the top five customers making up 25 percent and the top ten accounting for 40 percent.
Another business might generate 45 percent of its total revenue from one customer, with the remaining 55 percent spread across hundreds of smaller accounts. Those two businesses may have similar turnover and profit, but the risk profile is very different. There is no universal percentage at which customer concentration suddenly becomes a problem.
Buyers will look at the broader picture, including the industry, how long the customer relationships have existed, whether contracts are in place, the profitability of each account, how easily customers could switch suppliers, and how likely the revenue is to continue after the sale. In other words, concentration is not judged by one number alone. It is judged by how exposed the business would be if one or more important customers reduced their spending or left.
A large customer is not necessarily a weakness. In many cases, it can materially improve the quality and value of a business.
A major customer becomes more attractive when the relationship is stable, profitable, contractual, and difficult for competitors to displace.
For example, a business supplying an essential product to a major national customer under a long-term agreement may have highly predictable revenue. If the relationship has existed for many years, margins are healthy, service levels are strong, and the customer would face significant disruption from changing suppliers, the account may be viewed positively.
Large customers can also provide strategic advantages such as:
In these circumstances, concentration may still be considered during valuation, but the buyer may view the relationship as a valuable component of the business rather than simply a risk.
The existence of a written contract can significantly influence how buyers perceive a major customer.
A strong customer agreement may specify:
A buyer will examine these provisions carefully.
A five-year customer relationship supported only by informal purchase orders may be viewed differently from a five-year relationship secured by a current multi-year contract.
However, a contract is not automatically secure. Buyers will also review termination rights and change-of-control clauses. A contract that allows the customer to terminate immediately following a business sale may provide far less protection than the seller initially assumes.
Buyers will often examine how long the major customer has traded with the business.
A customer representing 30 percent of revenue after working with the company for 15 years may be viewed differently from a customer representing 30 percent of revenue that was acquired only six months ago.
A long history can demonstrate:
Historical stability does not guarantee future revenue, but it can provide buyers with evidence that the relationship has survived economic cycles, management changes, price increases, and competitor activity.
Buyers will also consider how easy it would be for the customer to move to a competitor.
Some supplier relationships are relatively easy to replace. Others are deeply embedded in the customer's operations.
High switching costs may exist where the supplier:
The harder it is for the customer to replace the business, the stronger the relationship may appear to a buyer.
Customer concentration becomes more concerning when losing one account could materially reduce profitability or threaten the viability of the business.
For example, imagine a business generating $10 million in annual revenue, of which $4 million comes from one customer.
If that customer leaves, revenue does not simply decline by 40 percent. The effect on profit can potentially be much greater because many costs remain fixed.
Rent, salaries, equipment finance, insurance, software, administration, and management costs may continue even after the revenue disappears.
As a result, a major customer that represents 40 percent of revenue could potentially represent a much greater proportion of profit.
This is why sophisticated buyers will analyse concentration using both revenue and profitability.
Consider two customers. Customer A represents 20 percent of revenue but generates very low margins because of aggressive pricing. Customer B represents 15 percent of revenue but generates exceptionally high margins and requires little additional overhead. Customer B may actually represent the greater financial dependency.
When preparing a business for sale, owners should therefore calculate:
This provides a much more accurate picture of the economic importance of each account.
Customer concentration becomes considerably more concerning when the relationship is also dependent on the owner. If the largest customer has dealt exclusively with the founder for 20 years, a buyer may worry that the relationship will disappear when the founder leaves.
This combines two major risks:
Before selling, owners should gradually introduce other senior employees into important customer relationships. Account managers, sales managers, operations managers, and senior executives should become known and trusted by key customers well before the sale process begins. The objective is for the customer to have a relationship with the company rather than exclusively with the owner.
Many Australian businesses have strong customer relationships that have developed over years without ever being formalised in a detailed contract. The relationship may operate through purchase orders, regular repeat business, or simply a long history of trust between the two parties. In practice, that can work perfectly well. From a buyer's point of view, though, the obvious question is what actually keeps that customer with the business after ownership changes. If there is no written contract, the seller should be ready to show other evidence that the relationship is stable and likely to continue.
That might include:
A clearer agreement can give buyers more confidence about future revenue. However, this needs to be handled carefully. Trying to push a long-standing customer into an unusual or overly restrictive contract shortly before a sale can create unnecessary tension and may do more harm than good. The priority should be to strengthen the relationship, not disrupt it.
A written contract may provide little comfort if it expires shortly after settlement. If a customer represents a significant proportion of earnings and its contract is due for renewal three months after the proposed sale, buyers may be reluctant to pay full value until the contract is renewed.
Where possible, sellers should review important customer contracts well before going to market and identify:
Contract renewal timing can have a surprisingly large impact on transaction certainty.
Some industries are naturally concentrated. A defence contractor, mining services company, infrastructure supplier, specialist manufacturer, or major project contractor may naturally generate substantial revenue from a small number of large customers. In these sectors, buyers may accept greater customer concentration because it is normal for the industry.
The important question becomes whether the business has a defensible reason for retaining those customers.
Buyers may look for:
A concentrated business with strong competitive advantages may still attract significant buyer interest.
Business valuations are influenced by both earnings and risk. Two businesses may generate identical profits but attract different valuation multiples because one has more predictable earnings. For example, a business with hundreds of recurring customers and no single customer representing a material proportion of revenue may be viewed as lower risk than a business generating the same profit from three major customers.
A buyer may therefore apply a lower multiple to the more concentrated business. The issue is not that the concentrated business is necessarily less profitable today. The concern is that future profits may be less predictable. Reducing customer concentration can therefore increase business value even if total revenue remains unchanged.
If a buyer is interested in the business but remains concerned about a major customer, the issue may be addressed through transaction structure rather than simply reducing the price.
A buyer may propose:
For example, part of the purchase price could become payable only if the largest customer remains with the business for 12 months after settlement. From the buyer's perspective, this transfers some customer retention risk back to the seller.
From the seller's perspective, it may mean that a portion of the sale proceeds remains uncertain after settlement. This is another reason to address customer concentration before commencing the sale process rather than waiting for a buyer to identify it during due diligence.
Owners preparing for sale should expect detailed questions about major customer relationships.
These may include:
Sellers who can answer these questions clearly are in a much stronger position during due diligence.
A useful preparation exercise is to create a customer concentration report covering at least the previous three financial years.
The report may show:
This allows the seller, business broker, accountant, and advisors to identify concentration issues before buyers begin their analysis.
If you intend to sell within the next one to three years, there may be time to improve the customer mix.
Strategies may include:
The objective is not necessarily to reduce revenue from the largest customer. Losing profitable revenue simply to improve concentration percentages would rarely make sense.
Instead, aim to grow other customer relationships faster so that the largest customer gradually becomes a smaller proportion of the total business.
This point is important. If a customer generates $2 million of profitable annual revenue, deliberately reducing its business simply because it represents a large percentage of sales may destroy value rather than create it. The better strategy is usually diversification through growth.
For example, if the largest customer represents $2 million of a $5 million business, it accounts for 40 percent of revenue. If the company grows other customers so total revenue reaches $8 million while retaining the same $2 million account, concentration falls to 25 percent without sacrificing any existing revenue. This strengthens the customer profile while also growing the business.
One of the most important steps before sale is institutionalising major customer relationships.
This means ensuring customers interact with several people within the business rather than one owner.
Consider:
When knowledge and relationships are held by the organisation rather than one individual, the business becomes more transferable.
Before sale, review your major customer agreements with an experienced commercial lawyer.
Where commercially appropriate, consider improving:
The objective should be to create commercial certainty without damaging valuable customer relationships.
Customer concentration should not be reviewed only when you decide to sell.
Include it in regular management reporting.
Management might track:
Monitoring these figures allows management to identify emerging dependencies before they become serious risks.
If customer concentration is likely to concern buyers, the best time to address it is well before the business reaches the market.
During the final 12 to 24 months, sellers should consider:
A year of deliberate preparation can materially change how buyers perceive a concentrated customer base.
Attempting to hide customer concentration is rarely effective. Experienced buyers will normally identify it quickly from financial records and due diligence information. A better strategy is to address it openly and explain why the relationship is durable.
Where applicable, a seller can demonstrate:
A well-explained concentration issue is often less concerning than one a buyer discovers unexpectedly. A major customer can be one of the most valuable assets in a business. It can provide recurring revenue, strong margins, operational efficiencies, market credibility, and years of predictable trading. But concentration becomes a valuation risk when too much of the company's future profitability depends on a relationship that could disappear.
For sellers, the objective should not be to avoid large customers. Large, profitable customers are generally worth pursuing. The objective is to build a business that is not vulnerable to the loss of any single relationship. By diversifying revenue, strengthening contracts, transferring relationships from the owner to the wider organisation, documenting customer history, and developing a strong new-business pipeline, owners can reduce concentration risk before going to market.
A large customer adds value when it strengthens the business. It reduces value when the business cannot survive without it. The difference lies in the durability of the relationship, the strength of the contract, the level of owner dependency, and the company's ability to replace the revenue if circumstances change.
