Private equity firms are increasingly drawn to lower mid-market businesses for their strong growth potential, loyal customer relationships and significant opportunities for operational improvement and value creation. However, these businesses often present a unique set of challenges than larger, more mature businesses.
Many are founder-led, with lean finance teams, evolving financial reporting and internal controls, and a reliance on key individuals rather than formal processes. While this doesn’t make them poor investments, in fact, many deliver strong returns it does mean investors need to look beyond the reported numbers.
Financial due diligence is not just about validating historical financial statements; it’s about assessing the sustainability, quality and predictability of future earnings. A business may appear profitable on paper, but investors must understand whether those earnings are sustainable and identify the operational and financial risks that could affect future performance.
While every transaction is unique, there are several financial red flags that private equity investors should examine closely during due diligence.
1. EBITDA Adjustments That Don’t Tell the Full Story
Normalising EBITDA is a standard part of financial due diligence, particularly in founder-led businesses. Owners often identify expenses they consider one-off, exceptional or personal in nature, and many of these adjustments may be justified.
However, each adjustment should be carefully validated. An expense labelled as “one-time” may have occurred repeatedly or simply represent a normal operating cost. Accepting adjustments without scrutiny can materially overstate the business’s earning capacity.
The goal is not to reject every adjustment, but to identify those that genuinely reflect sustainable earnings after acquisition, providing a more accurate view of ongoing operating performance.
2. Poor Quality of Earnings
Strong EBITDA doesn’t always reflect a business’s true performance. Investors need to assess not just how much the business earns, but how reliable and sustainable those earnings are.
Reported EBITDA may be inflated by one-off transactions, non-recurring income, temporary cost savings or accounting treatments that won’t persist after acquisition. Conversely, it may mask declining margins, rising costs, pricing pressure or customer-specific concessions that could erode future profitability.
A Quality of Earnings (QoE) analysis helps separate recurring operating performance from temporary or exceptional items, providing a clearer view of the business’s sustainable earnings power. This enables more accurate valuations, better-informed negotiations and reduces the risk of paying for earnings that cannot be maintained after closing.
3. Dependence on a Few Customers
Customer concentration is one of the most common risks in lower mid-market businesses. A company may be growing strongly, but if 40–50% of its revenue comes from a single customer, it is heavily dependent on that relationship. If the customer leaves after the acquisition, the impact on revenue, profitability and cash flow can be significant.
This doesn’t necessarily make the business a poor investment, but the risk should be clearly understood. Investors should assess the strength of key customer relationships, contract terms, retention history and the likelihood those relationships will continue after a change in ownership. They should also evaluate how easily lost revenue could be replaced if a major customer were to exit.
4. Cash Conversion and Working Capital
Profitability is important, but strong cash generation is equally critical.
If profits are growing while operating cash flow remains weak, investors need to understand why. This may reflect expansion investments or temporary working capital demands, but it could also signal slower customer collections, rising inventory or increasingly difficult-to-collect receivables.
Working capital is equally important, as it determines how much additional funding the business may require after acquisition. Reviewing cash flow alongside working capital trends helps investors assess whether reported profits are being converted into cash and whether the business can support future growth without placing unnecessary pressure on liquidity.
5. Weak Processes, Controls and Reporting
Many lower mid-market businesses outgrow their internal processes. As a result, key activities across finance, operations, sales, procurement and service delivery often rely on informal practices rather than documented, consistent processes.
Financial reporting may depend on spreadsheets, reconciliations may be inconsistent, and management reporting may be prepared only when needed. Similar weaknesses often exist in procurement, inventory management, pricing, project delivery and customer operations.
While these issues do not necessarily indicate poor performance, they increase operational risk, reduce the reliability of reporting and forecasting, create opportunities for errors and inefficiencies, and make post-acquisition integration more challenging.
Investors should assess whether the business has scalable processes, effective governance and appropriate internal controls to support its next phase of growth.
6. Founder and Key Person Dependency
Many lower mid-market businesses rely heavily on founders and a small group of experienced employees to manage customer relationships, pricing, supplier negotiations and other critical operations. While this often contributes to the company’s success, it can also create significant post-acquisition risk.
The departure of these individuals may disrupt customer relationships, operational continuity and decision-making. Investors should therefore assess whether knowledge and responsibilities are embedded across the organisation or concentrated in a handful of key people. Businesses that rely on individuals rather than documented processes are typically harder to scale and integrate.
Where appropriate, investors should negotiate transition arrangements that retain founders and other key personnel after completion, helping preserve customer relationships, transfer institutional knowledge and minimise operational disruption.
7. Commercial Terms That Distort Profitability
Reported EBITDA tells only part of the story. The commercial terms underpinning customer and supplier relationships can materially affect future profitability, cash flow and the overall investment thesis.
Long payment terms, retrospective rebates, volume discounts, fixed-price contracts, service level penalties and minimum purchase commitments can all reduce future earnings or cash flow without being obvious in the financial statements. Likewise, favourable terms negotiated by a founder or long-standing management team may not be sustainable after an acquisition.
Financial due diligence should therefore look beyond the numbers to assess whether commercial agreements support the business’s sustainable earnings, cash flow and debt service capacity—or introduce risks that could undermine the investment case.
8. Don’t Mistake Peak Performance for Sustainable Performance
Businesses often come to market after a period of exceptional financial performance. While this may reflect genuine operational improvements, it can also be driven by temporary factors that are unlikely to persist.
Favourable market conditions, supply shortages affecting competitors, unusually strong demand, deferred expenditure or one-off contracts can all inflate earnings before a transaction. If these factors are not identified during due diligence, investors risk valuing the business on earnings that are not sustainable.
Rather than relying on recent trading alone, investors should assess performance over multiple years to determine whether growth reflects a structural improvement or a cyclical peak. Normalising earnings provides a more reliable basis for valuation, debt capacity and expected returns.
Paying an acquisition multiple based on peak EBITDA can materially reduce returns if earnings subsequently normalise. Financial due diligence should therefore focus on sustainable earnings rather than simply validating the business’s strongest historical performance.
Conclusion
Successful financial due diligence goes beyond validating historical financial statements. It assesses the sustainability of earnings and identifies the financial and operational risks that could affect future value creation.
Not every red flag is a deal breaker. More often, these findings help investors ask better questions, negotiate more effectively and develop stronger post-acquisition plans. Identifying risks early enables more informed investment decisions.
Ultimately, successful private equity investing is not about buying businesses with the highest reported EBITDA, but those with the most sustainable earnings and greatest potential for value creation. Disciplined financial due diligence validates the investment thesis, challenges assumptions and uncovers risks before they become costly post-acquisition surprises.