Sixty Per Cent of Everything: Auditing Your Dependence on a Single Client

There is a particular kind of silence that follows the loss of a dominant client. The invoices stop, the weekly calls stop, and the orders that filled the production schedule simply stop arriving. For the UK small business that has quietly allowed one customer to become 60% of its revenue, that silence is not an inconvenience — it is an existential event.

The uncomfortable truth is that few owners arrive at that position deliberately. Client concentration creeps. A promising account grows, capacity is reallocated to serve it, new enquiries are declined because the workshop is full, and within three years the business has, in effect, become a subcontracted department of someone else's company — without the security of employment.

Measuring the Exposure Honestly

The first step is a straightforward audit. Calculate the proportion of turnover attributable to your largest client over the last three financial years, not just the most recent one. A trend is more revealing than a snapshot: a client moving from 30% to 55% over three years tells you the trajectory, and trajectories are what you can still change.

Then look beyond revenue. Ask three questions:

• Margin, not just turnover. A dominant client often commands discounts, extended payment terms and bespoke processes. A 60% client on 90-day terms and thin margins may contribute far less than the headline figure suggests.
• Operational dependency. Does a meaningful share of your staff, machinery or stock exist solely to serve this account? If the contract ended tomorrow, what would be idle?
• Contractual position. What notice period applies? Is there a break clause? Is the relationship documented at all, or does it rest on years of goodwill and a purchase order history?

If the honest answer to these questions makes you uneasy, that discomfort is the audit working as intended.

The Terms Drift You Didn't Notice

Concentrated relationships rarely stay balanced. Scope creeps — the 'small favour' that becomes an unpaid service. Payment terms stretch, first to 45 days, then to 60, because you dare not chase. Procurement teams at larger clients know their leverage and use it, particularly in the current economic climate when every buyer is under pressure to squeeze suppliers.

The result is a slow transfer of power. By the time the client's new finance director proposes a 'supplier consolidation exercise', you are no longer in a position to negotiate; you are in a position to comply.

Rebalancing Without Sinking the Ship

The obvious remedy — diversify — is easier said than done when your capacity is committed. A practical sequence looks like this:

1. Protect margin first. Renegotiate terms on the dominant account where you can, however modestly. Every point of margin recovered buys you time and options.
2. Cap the ceiling. Set an internal rule that no single client shall exceed, say, 40% of turnover, and treat new enquiries that would breach it as a signal to raise prices rather than decline the work.
3. Ring-fence business development time. Reserve a fixed number of hours each week for pipeline work, even when the dominant client is demanding. Capacity is an argument for hiring or subcontracting, not for abandoning the pipeline.
4. Build a financial buffer. Model the cash impact of losing the client on the notice period in your contract. If the answer is that you could not meet payroll within a quarter, the buffer is not a nice-to-have.

Renegotiating From Strength

None of this requires you to treat a valuable client as an enemy. The strongest position from which to discuss terms is one in which you are not desperate — and the only way to get there is to reduce the dependency itself. Ironically, businesses that diversify often find their relationship with the major client improves: they become a supplier with options, rather than one with needs.

If you would like an independent view of your revenue concentration, contractual exposure and the practical steps available to rebalance, HCLP Advisory works with owner-managed businesses across the UK on exactly these questions. The best time to have that conversation is while you still have the choice.