Client Concentration Risk: How Much Revenue From One Client Is Too Much?
When one client pays a third of your salaries, every conversation with their procurement team carries a weight that nobody else in the business can quite see, and that weight is what investors and lenders mean when they talk about client concentration risk. It is rarely a sign that something has gone wrong, because in most founder-led technology services firms the dominant account arrived as a success: a client who trusted you early, expanded steadily and now sits at the centre of the P&L. The difficulty is that the same account which built the business can quietly start to govern it, and the effects appear in pricing, hiring and strategy long before anyone mentions a sale.
What client concentration risk actually measures
Concentration is usually expressed as the share of revenue coming from your largest client, and then from your top three and top five clients combined, measured over a trailing twelve months rather than a single good quarter. Gross profit concentration matters as much as revenue, because a large account run at thin margin tells a different story from one run at healthy margin, and an acquirer will look at both.
The measure is really a proxy for a question about fragility, which is how much of the business would survive if a single decision-maker in a single client organisation changed their mind. A new CIO, a group-wide vendor consolidation or a budget freeze in someone else's boardroom can all remove revenue that you did nothing to lose.
The thresholds investors and lenders tend to use
There is no statutory line, but in practice buyers, private equity firms and lenders work with broadly similar bands, and knowing where you sit tells you how much of the conversation will be about this one issue.
| Largest client share of revenue | How it is usually read |
|---|---|
| Under 10% | Healthy, rarely discussed beyond a line in the diligence report |
| 10% to 20% | Noted and questioned, particularly on contract terms and relationship depth |
| 20% to 30% | A material risk that tends to affect price, structure or both |
| Over 30% | Often a deal-shaping issue, and for some investors a reason to wait |
Many investors also look at the top five clients together, and a combined share above roughly half of revenue attracts scrutiny even where no single client breaches the bands above. Lenders apply similar thinking in covenant discussions, since their concern is whether cash flow survives the loss of one account.
Rule of thumb: if losing your largest client would force redundancies within a quarter, you have a concentration problem regardless of what the percentage says.
Context changes the reading, which is worth remembering before you panic. A multi-year contract with termination protection, several independent buying teams inside the client, and a long history of renewals all soften the risk, whereas a rolling statement of work held together by one sponsor who likes your founder hardens it. The wider picture of what investors look for in a technology services business explains how this sits alongside recurring revenue and margin quality.
How concentration discounts valuation
A buyer pays for future cash flow, and concentration makes that cash flow less certain, so the discount tends to arrive through three routes rather than one. The first is a lower multiple, applied because the revenue base is judged riskier than a comparable business with a spread of clients. The second is structure, where more of the price is deferred into an earn-out tied to the dominant client renewing, which moves the risk back onto you. The third is the conditions attached to completion, such as a requirement that the client confirms its intention to continue, which is the reference call you dread made considerably more formal.
Concentration and founder dependency frequently travel together, because the largest relationship is so often held personally by the founder, and when that is the case the two discounts compound. The mechanics of that overlap are covered in what founder dependency costs at exit, and the questions a buyer's team will ask sit in the operational due diligence checklist.
The constraints it creates long before any sale
The more damaging effects are the ones you live with every week, which is why this is worth addressing even if an exit is years away.
Pricing power drifts to the client
When one account funds a large part of the payroll, you become reluctant to raise rates, push back on extra work or enforce change control, and the client learns this without anyone saying it. Margin erodes gradually through concessions that each looked reasonable at the time, which is the same dynamic described in the piece on stopping scope creep without souring the relationship.
Hiring follows one client's roadmap
Resourcing decisions start to be made around the dominant account's technology choices and timelines, so the capability you build is shaped for them rather than for the market you want to win, and one lumpy quarter on their side creates a bench on yours.
Strategy becomes defensive
Leadership attention bends towards keeping the large client happy, which is rational in the short term but crowds out the investment in sales, marketing and new propositions that would reduce the dependency in the first place. We call this the anchor account trap, where the client that steadies the business also stops it moving.
A realistic 12 to 18 month plan to dilute a dominant account
Dilution means growing everything else faster than the large account rather than shrinking it, and the aim is to reduce the percentage without damaging a relationship that remains valuable. Eighteen months is realistic because new clients take time to win and longer to expand, and anything faster usually means discounting to buy revenue you will regret.
- Months one to three: measure and protect. Establish trailing revenue and gross profit by client, map every relationship inside the dominant account beyond the founder, and review the contract for notice periods and renewal dates. Where possible, extend terms or broaden the sponsorship base while the relationship is good, because that is the moment it is easiest.
- Months three to six: decide where growth comes from. Identify two or three adjacent segments where the work you do for the large client is credible elsewhere, and build a pipeline target sized to what the percentage needs to become, rather than a general wish to sell more.
- Months six to twelve: build a sales engine that is not the founder. This is the hard part, since concentration usually persists because new business depends on one person's time. Assign ownership of pipeline, set coverage targets and review them monthly at leadership level.
- Months twelve to eighteen: expand new accounts and rebalance delivery. Treat second and third projects with newer clients as the priority, move experienced people onto them, and let the dominant account run on a team that does not include the founder in every decision.
Worked example: a business with revenue of £5m and one client at £2m sits at 40%. If that client holds flat and the rest of the book grows from £3m to £4.5m over eighteen months, concentration falls to roughly 31% without losing a pound from the anchor account, which shows why growth elsewhere matters more than any change to the large client.
Throughout, keep delivery quality on the dominant account visibly high, because a client who senses they are being deprioritised is the fastest route to the outcome you are trying to insure against.
Where Vitori fits
Concentration is rarely solved by a strategy document, since the percentage only moves when the business builds a sales capability, delivery structure and leadership rhythm that do not route through the founder, and those are operating changes that have to hold for long enough to show in the numbers. Vitori works on exactly that through the Operational Scale Framework, assessing Growth, Delivery and Operations together, and in the Operator model embeds as fractional leadership to implement the plan rather than hand it over. It is not the right answer if the issue is purely contractual, where a good lawyer and a well-timed renewal conversation may be enough, and whether you work with Vitori or anyone else, the goal is the same: a business that runs, and scales, without the founder in every decision.