Client concentration — take the expansion or protect the capacity
The hypothesis put to the council
An independent consultant whose largest client is already 45% of revenue should turn down that client's offer to expand the engagement, and spend the capacity on diversifying instead.
The situation
A composite. Every number below is a working fact for the debate, and describes no real person or company.
Independent consultant, six years solo. Operations and systems work for mid-market logistics companies. Trailing twelve months $265,000 across three clients.
The largest is $120,000 — 45% of revenue. Three years old, never at risk, and the sponsor there was promoted last year and is a genuine advocate. They have now offered a further $90,000 over twelve months for a second workstream, which would take them to roughly 58%.
Accepting consumes essentially all remaining capacity; it cannot be done alongside meaningful business development. The other two clients are $85,000 and $60,000, both stable. Pipeline is two warm conversations, neither past a first call, after 18 months with no systematic business development because referrals have been enough. Nine months of personal runway, no debt.
The verdict
Invalidated
The expansion is the higher-probability channel. Existing-client work converts far better than new business, and the outbound channel here has produced no systematic activity for eighteen months — so the hypothesis trades a closed offer for an unproven one.
The severity is also lower than the standard concentration warnings assume. This is a solo operator with no payroll: losing the big client leaves $145,000 from two stable relationships and nine months of runway, which is a survivable shock rather than an extinction event. The heuristics that treat 40%-plus as a red line were written for businesses with fixed costs.
Where the verdict flips
Probability of closing one new client worth $80,000/year within twelve months of protected capacity, at 47%
Below 47%, accept the expansion. Above 47%, decline it or cap it.
This reframes the decision usefully. It is not really a question about concentration risk — it is a question about how good you honestly are at winning new work when you actually try. A consultant with a repeatable outbound motion should decline; one who has coasted on referrals for eighteen months almost certainly should not, because they are trading real revenue for a capability they have not demonstrated.
Where the council disagreed
Kept as it came out of the session. The chairman states which way the evidence points, but the split is the useful part.
Whether 58% hands the client a veto
The dissenting case is that past 58% the client effectively controls the business — pricing, scope and timing all become things you accept rather than negotiate. That is a real cost even if the relationship never sours, and it does not show up in any risk calculation based on survival.
Whether the promoted sponsor is reassurance or risk
The session treated the sponsor's promotion as a stability signal. The counter-argument is that it is the opposite: newly promoted people move on at materially higher rates in the months right after promotion, and this relationship's safety rests on one person.
Whether the second workstream is bounded
The dissent wins outright if the new workstream is open-ended. A bounded twelve-month scope with a written end date is a temporary concentration; an open-ended one is a permanent restructuring of the business around a single client.
The strongest case against this verdict
Stated so its advocate would accept it.
At 58% the client holds a veto over the business, and the reassurance everyone points to — the promoted, advocating sponsor — is itself the single point of failure. Newly promoted employees leave at a much higher rate in the month after promotion than they otherwise would.
That case wins if the second workstream is open-ended rather than a bounded twelve-month scope.
First three moves
This week
Accept in writing, but negotiate the terms that defuse the concentration: IP retention with a client licence, 60-day mutual notice, a written end date on the scope, and an introduction to a second stakeholder so the relationship does not rest on one person.
Within 30 days
Launch one fixed-shape productized audit — one page, one price, one deliverable — and sell it to the two warm prospects. This keeps a business-development motion alive at low capacity cost.
Within 60 days
Raise rates on the two smaller clients at their next renewal, and put a calendar block 30 days before the expansion's end date to decide where that capacity goes next.
The structure of move one is the whole verdict. Accepting is fine; accepting without an end date is what turns a good year into a dependent business.
How this goes wrong
Failure mode
The expansion quietly becomes permanent. The end date passes, the work continues, business development never restarts, and the concentration that was supposed to be temporary is now the shape of the business.
Early warning signal
The written end date arrives without a scheduled conversation about what replaces that capacity. If nothing is on the calendar 30 days out, it has already happened.
What we checked
All 5 factual claims in this session were checked against primary sources afterwards, and 3 survived as sourced fact. The most consequential are below; the outcome of every one is in the fact-check ledger. The reasoning above stands on its own. Most of the numbers the council reached for do not.
Verified and citable
- Professional-services firms win existing-client RFPs at a median 62%, against roughly 40% for new-business bids — a gap of more than 20 points. QorusDocs 7th Annual Proposal Management Benchmark Study, 2023, n=145 of 224 respondents. Vendor-sponsored survey with disclosed sample and method, not independent research. Source
- 29% of people left their employer within a month of their first promotion, against a modelled 18% had they not been promoted — a near two-thirds increase in flight risk. ADP Research Institute, Today at Work Issue 3, September 2023, from 1.2 million US workers' job histories 2019-2022. Note the 18% is a modelled counterfactual for the same people, not a separately observed group. Source
Cut — no locatable source
- The idea that 40-50% single-client revenue is the recognised danger threshold. No academic, regulatory or major-institutional source establishes it. Advisory blogs assert anywhere from 10% to 50% with no primary study behind any of them, and the variance is itself the tell.
- Any figure for how long a solo consultant takes to land an $80,000-plus engagement, or their outbound close rate. No study covers independent operators at this deal size; the available benchmarks describe enterprise sales teams and do not transfer.
The council's assumptions, not established facts
- The 47% threshold itself. It is the council's own derivation from the case file's numbers, not a benchmark — the reasoning is checkable but the figure is not sourced.
- The widely-repeated '60-70% chance of selling to an existing customer versus 5-20% for a new prospect'. It traces to a real reference text but no one quotes the underlying study, and it circulates almost entirely through secondary citation.
Worth noting what the check found on concentration itself: the regulatory and institutional consensus sits far below the folk threshold. US GAAP requires disclosure of any customer above 10% of revenue, and lenders and acquirers typically start asking questions in the 15-25% band. The number everyone repeats as the danger line is roughly double where the people who price this risk professionally begin paying attention.
How this session ran
- Council
- Claude Opus 5 · GPT-5.5 · Gemini 3.1 Pro · Grok 4.3 · Kimi K2.6
- Chairman
- Grok 4.3
- Written for
- Solo consultants, fractional executives, one-person services businesses
- Shape
- Five independent proposals, anonymized peer review, chairman synthesis. One round.
Also in the ledger
A Council Audit on your own decision
Every external claim is checked against primary sources before you read it. What survives is cited. What doesn't is printed as cut, the same way it is above.
You get one recommendation and the number at which it flips, the strongest argument against it, and the first three moves in order.
$299. Written brief in 48 hours. No call.