Client Concentration Risk

Client concentration risk is the vulnerability that comes from having too much of your revenue dependent on too few clients. If one client represents 25% of your agency's revenue and they leave, you've just lost a quarter of your income — but your costs (salaries, rent, software) don't drop by 25%. You're suddenly burning cash and scrambling to replace a massive chunk of revenue.

The industry rule of thumb is that no single client should represent more than 15-20% of your AGI, and your top 3 clients combined shouldn't exceed 40-50%. Beyond those thresholds, you're exposed to client concentration risk — the business equivalent of putting all your eggs in one basket.

Concentration risk comes from both obvious and subtle sources. The obvious source is a whale client that dominates your revenue. The subtle source is having multiple clients in the same industry that could all be affected by the same market downturn — if 60% of your revenue comes from real estate clients, a housing market crash hits all of them simultaneously. Geographic concentration is another form: if all your clients are local businesses in one market, a regional economic downturn can cascade through your portfolio.

Client concentration is the most common cause of agency failure and the single biggest discount factor in agency valuations. Acquirers will significantly reduce their offered multiple — or walk away entirely — if losing one client could destabilize the business. A $5M agency with balanced revenue across 30 clients is worth materially more than a $5M agency where one client represents $2M.

Beyond valuation, concentration risk creates a toxic power dynamic. When a client knows they represent a huge percentage of your revenue, they have leverage — and they'll use it. They'll demand lower rates, faster turnarounds, more revisions, and priority over your other clients. You'll accept these terms because you can't afford to lose them, which ironically makes you even more dependent.