Customer Concentration: When to Worry, When Not To
Customer concentration is one of the first things lenders, investors, and acquirers analyze. The usual rule of thumb — “no customer over 10-15%” — is sometimes right and frequently wrong. Three questions matter more than the headline percentage.
Question 1: Is the relationship structurally embedded?
A 30% customer with a 5-year contract, integrated workflows, switching costs measured in months, and shared technology infrastructure is structurally different from a 30% customer with no contract who buys what’s cheapest. The first is durable; the second is fragile. The headline percentage looks identical.
Lenders and investors who do real diligence ask: what would the customer have to do to leave? If the answer involves operational disruption, contractual penalties, or significant re-platforming, the concentration is less risky than it appears.
Question 2: Is the relationship growing or declining?
A 25% customer growing 20% year-over-year is more reassuring than a 15% customer in decline. The trajectory matters more than the snapshot. Pull a five-year customer history; the trend line tells the story.
Question 3: What’s the next-customer pipeline look like?
Concentration becomes risk when the business cannot replace the lost revenue. A 35% customer is dangerous if losing them would take 18 months to backfill. A 35% customer is manageable if a $10M replacement pipeline exists with 60% probability customers.
Three concentration patterns and what each means
Anchor tenant. One large customer (25-50% of revenue) plus a long tail of smaller accounts. Common in B2B services, government contracting, healthcare. Usually workable if the relationship is structurally embedded and the long tail is growing.
Top three. The top three customers represent 50-70% of revenue. Common in industrial supply, B2B distribution, professional services. Risk is moderate; loss of any one is survivable, loss of two simultaneously is not.
Long tail dominant. No customer over 5%. Common in consumer businesses, e-commerce, retail. Concentration risk is low; customer acquisition cost and retention are the central concerns instead.
What to do about concentration
- Structural embedding. Negotiate longer contracts. Integrate technology. Embed in customer workflows. Make leaving costly.
- Pipeline depth. Maintain pipeline equal to 1.5-2x your largest customer’s annual revenue at all times.
- Vertical or geographic expansion. Reduce concentration by serving adjacent customer types.
- Transparency. Don’t hide concentration from lenders or investors. They will discover it; surfacing it with mitigation context is far better than letting them find it.
For lenders and investors evaluating your business
Lead with the structural embedding. Show contract length, integration depth, switching cost. Provide pipeline coverage. Demonstrate that loss of the top customer is survivable. The concentration question is rarely a yes/no; it’s almost always a “depends on the answer to the three questions above.”