Service Business Due Diligence:The Eight Question Audit
Service business due diligence in eight questions: is the service an asset or you, how the money behaves, and how growth works. Score yourself first, today.
Here's an exercise worth doing even if you never intend to sell: imagine the day a buyer runs service business due diligence and takes your business apart. They don't start with your revenue. They don't care about your reputation, your awards, or how hard you work. They run through a short list of structural questions — and your answers place your firm somewhere on a spectrum that runs from one times revenue to fifteen times revenue.
The list isn't secret. John Warrillow laid out the underlying research in Built to Sell and The Automatic Customer. What shocks founders isn't the questions. It's their own answers.
I once walked a consulting founder through this exact audit. Twelve years in business. Around $1.2 million in annual revenue. A client list he was proud of. But every dollar was project work, re-sold from scratch each quarter. His three largest accounts made up 55% of revenue. He held every key relationship personally. No written methodology, no proprietary tooling, nothing recurring.
Strip him out of the business and the business disappeared. A buyer would see $1.2 million of revenue and offer perhaps $1.5 million for the lot — because the founder, not the firm, was the asset.
That gap between what you earn and what you've built is the whole point of this service business due diligence audit. And it matters long before any sale, because the same answers that make a firm sellable also make it durable, profitable, and capable of running without you. Below are the eight questions, regrouped into three parts: the service itself, the way the money behaves, and the mechanics of growth.
Before You Begin: Scoring a Service Business Due Diligence Audit
Scoring Rules
Rate yourself from 1 to 10 on each question. A 1 means the capability simply doesn't exist in your business. A 10 means it's built, working, and would survive scrutiny from a skeptical buyer. Be brutal. Aspirational answers only postpone the reckoning.
Part One: Is the Service an Asset or Is It You in Service Business Due Diligence
Questions 1-3
Question 1: Can the work be delivered without you? Not approximately. Not at a lower standard the client tolerates. The test is whether a trained practitioner who isn't you can run your method and produce results the client rates as excellent. Everything else in this audit hangs on this answer, because a method that lives only in your head can't be transferred, certified, or sold. What makes a method transferable is boring on purpose: written steps, decision trees for the situations that come up repeatedly, and quality standards a stranger could be held to. A 1 here means no engagement happens without your hands on it. A 10 means trained practitioners deliver routinely and clients stay happy.
Question 2: Are clients buying the result — or the relationship? These look identical from the inside and are opposites from a buyer's perspective. Outcomes can be reproduced by anyone trained in the method. The experience of working with you specifically cannot — and a business built on that experience is a personality with a payroll, not an asset. Score a 1 if what clients really value is your personal attention. Score a 10 if they can name concrete, measurable improvements the methodology produced no matter who showed up to deliver it.
Question 3: Is the method actual property? An "approach" you describe in sales calls is not intellectual property — it's a description of what every competitor also claims to do. Property has a name you've trademarked, materials you've copyrighted, and a documented delivery system other people can be certified against. Score a 1 if nothing is named or written down. Score a 10 if the name is protected, the materials are protected, and the delivery process lives in an operations manual rather than your memory.
Part Two: How the Money Behaves
Questions 4-6
Question 4: Does revenue compound — or restart from zero? A one-off project pays you once and then asks you to go win it again. Annual reassessments of a diagnostic, quarterly advisory arrangements, platform subscriptions — these stack on top of each other instead of resetting every quarter. Score a 1 if every piece of work is a standalone project. Score a 10 if 70% or more of revenue recurs each year through renewals, subscriptions, or scheduled reassessments.
Question 5: Who finances the work — you or the client? Cash timing is destiny in a service firm. When clients pay an annual fee in January for a year of access, they fund your operations. When you invoice after delivery and wait 30-60 days, you fund theirs. Score a 1 if you're routinely waiting sixty days past delivery to get paid. Score a 10 if most revenue arrives upfront — annual fees, prepaid assessments, retainers collected before the work begins.
Question 6: How exposed are you to one phone call? If a single client clearing 15% of your revenue can put the business at risk by leaving, a buyer prices that risk in — and so should you. Warrillow describes the antidote as the "Switzerland Structure": neutral, balanced, dependent on no single party. Score a 1 if one client accounts for more than 40% of revenue. Score a 10 if none exceeds 10%.
Part Three: The Growth Mechanics
Questions 7-8
Question 7: Whose departure could sink it? Founder dependency gets all the attention, but the question is broader: is there anyone — a rainmaker, a star deliverer, you — whose exit would cost clients, revenue, or delivery capacity? Score a 1 if the business is effectively one person wearing a company name. Score a 10 if every role is documented, relationships belong to the institution rather than to individuals, and nobody carries more than 20% of the firm's capacity.
Question 8: Does growth require bodies? Trace your unit economics. If adding $200,000 of revenue means hiring another consultant every time, growth is linear and margins never improve — you're renting out increasingly expensive hours. If your model licenses the methodology, the same $200,000 might arrive by certifying two more partners at marginal cost. Score a 1 if headcount rises in lockstep with revenue. Score a 10 if the model has decoupled the two.
The Number You Get
Totals Range From 8 to 80 — Here's What Each Band Means
65-80 — Platform territory. The architecture is built. Your work now is sharpening it: grow the recurring percentage, deepen the data your method generates, widen the practitioner network. Few service businesses are designed this well.
45-64 — Mid-transition. The skeleton of a scalable business is visible but incomplete. Most methodology businesses sit here in their first two years, and it's actually the highest-leverage place to be: find the questions pulling the total down and every point you recover compounds.
25-44 — Founder-dependent. The intellectual property is real but trapped — in your head instead of on paper. The job is extraction: write the methodology down, build the diagnostic instrument, and stand up one delivery process that runs without your personal involvement.
Below 25 — A practice. Plenty of professionals have rich, satisfying careers running practices. Just be honest about what it is. What separates a practice from a platform isn't talent — it's architecture.
The founder from the opening? His service business due diligence total was 19. Twelve years of effort had grown the revenue while leaving the structure exactly where it started. That's the standard trap: founders refine the work endlessly and never construct the machine around it.
The Repair Order
One Question at a Time, Lowest Score First
Resist the urge to attack all eight at once — that path produces motion without progress. Take your single lowest score and work it.
Weakest on Question 1 (delivery without you)? Documentation comes first. Record yourself across your next five engagements, narrating the decisions as you make them, and turn the transcripts into an operations manual one process at a time.
Weakest on Question 4 (compounding revenue)? Redesign the engagement model itself. Could the diagnostic become an annual reassessment? Could project work be repackaged as a retainer? Is there a subscription tier for ongoing advisory hiding inside what you already do?
Weakest on Question 6 (concentration)? That's a pipeline problem wearing a delivery costume. You need more clients at smaller ticket sizes, which means more leads, which usually means sharper positioning — so the right clients arrive consistently instead of a few large accounts carrying everything.
Weakest on Question 5 (cash timing)? Rebuild billing. Trade monthly invoices for annual prepayment with a modest discount. Take retainer deposits before work starts. Move certification fees from quarterly to annual collection.
Improvements feed each other. A method that's teachable lets you certify practitioners, which fixes scalability. Cash collected upfront buys the time to document, which fixes teachability. Two or three points on one question tend to drag others upward.
Then make service business due diligence a quarterly ritual. Write the number down, watch the trend. A flat line means you're accumulating revenue without accumulating value — and those are not the same thing.
Two Firms, One Revenue Line
Why Identical Income Produces Wildly Different Wealth
Picture two consulting businesses, each doing $1 million a year. One audits at 22; the other at 68. The first might fetch $1-2 million. The second, $8-15 million. Identical revenue, an order-of-magnitude gap in wealth — and the founders' intelligence had nothing to do with it. One designed deliberately against these eight questions; the other polished delivery and never inspected the architecture underneath.
Don't treat service business due diligence as a pre-sale checklist. Treat it as the design spec for a business worth owning in the first place. Take the score. Sit with the number. Then go fix the lowest one.