[Case002] When You Are 40% of the Target’s Revenue: How to Handle Valuation in M&A

If your company already accounts for a large share of the target’s revenue, should you subtract it from the price? The instinct is understandable—but usually wrong. In Japan’s SME market, where decades-long trading relationships are the norm, this question demands particular care.

Start with Standalone Value—Don’t Skip Ahead

The first step is always to calculate the target’s standalone value using standard methods: DCF, market multiples, or asset-based approaches. At this stage, all customer relationships—including your own—should be treated as arm’s-length commercial transactions. The standalone value reflects what the business is worth as it currently operates, independent of the acquirer’s identity.

A common mistake is to jump straight to deducting the buyer-related revenue. If you represent 40% of sales, the reasoning goes, that portion vanishes post-acquisition. But this ignores real economic effects: internalization may generate cost savings, improve supply stability, reshape margin structures, and eliminate redundant overhead. Simply subtracting revenue captures none of this. Worse, it conflates a change in revenue classification with a destruction of value—two very different things.

Same Concentration, Different Risk

The View from Other Buyers

The target’s value depends on who is looking at it. For other potential buyers, your 40% share represents customer concentration risk—the possibility that you could reduce or terminate orders at any time. They will discount accordingly, applying higher discount rates or probability-weighted scenarios that assume partial revenue loss.

The View from You, the Incumbent Customer

For you, however, that same dependency is a source of stability and potential synergy. Acquiring the target locks in the supply relationship, may yield reduced procurement costs, tighter operational coordination, and strategic supply chain control. The same 40% that creates downside for others creates upside for you.

Key insight: Rather than deducting revenue, separate the analysis. Adjust standalone valuation for concentration risk (via discount rates or scenario analysis), then evaluate buyer-specific synergies independently. This avoids double-counting.

The Japan Factor: When Concentration Is the Business Model

International investors often apply Western frameworks reflexively—treating any high customer concentration as a red flag. In Japan’s SME landscape, this can be a costly misread.

Concentration as the Foundation, Not an Anomaly

Japanese commercial relationships are shaped by keiretsu-era logic and long-term trading customs (torihiki-saki kankei). A single customer accounting for 40% of revenue is frequently not an anomaly but the foundation of the business, sustained over decades through personal trust and unwritten mutual obligations. A 40% dependency maintained for 20 years is qualitatively different from one won via competitive RFP two years ago—the switching costs, both economic and social, are far higher.

The Foreign Acquirer Paradox

For foreign acquirers, there is an added paradox. Ownership change—especially to a non-Japanese buyer—can itself destabilize these ties, since customers may have been loyal to the owner personally. But if the foreign buyer is the concentrated customer, the dynamic flips: the acquisition secures a relationship that might otherwise erode during transition.

Competitive Bidding and Seller Psychology

In auction processes, buyers worry that competitors will bid higher because they don’t face the same revenue elimination concern. But those competitors carry their own concentration risk discounts—and the outcome depends on how each bidder interprets the dependency, not on headline numbers alone.

This is especially true in Japan, where many SME owners prioritize employee welfare and long-standing customer continuity over maximizing sale price. A buyer who is already embedded in the target’s commercial ecosystem—and who can credibly promise stability through the transition—holds an advantage that no bidding premium can replicate. Understanding this seller psychology is itself a competitive edge.

Strategic Pricing Checklist

1. What is the target’s standalone value?
2. How do other buyers perceive the concentration risk?
3. What synergies are unique to us as the incumbent customer?
4. How deep is the trading relationship beyond contract terms?
5. What price reflects our incremental value?

Conclusion

Directly deducting your own revenue share from a target’s valuation is almost always the wrong approach. Separate standalone value, risk adjustments, and buyer-specific synergies instead.

What looks like a valuation problem is often a perspective problem. In Japan’s relationship-driven market, the buyer who understands this distinction doesn’t just price better—they win the deal.

About the Author

Hiroki Sato — Group CEO, BulkUp Group

MBA – Kyoto University

Entrepreneur in Residence – University of Nottingham, UK

Former MUFG. Former PwC Japan (DEALS, Business Recovery Services). BulkUp Consulting KK is a Tokyo-based boutique M&A advisory firm specializing in integrated, one-stop due diligence for SME transactions—covering financial, tax, legal, and labor DD, valuation, and SPA drafting at a fraction o