Due Diligence: What a Buyer Asks About What You Know

There is a point in most business sales where the conversation stops being about the numbers.

By then the accounts have been through the wringer. Revenue is where you said it was, the margins hold, the customer list is real, and everybody is reasonably satisfied. Then somebody on the buyer's side asks a question that sounds almost casual. If your operations director were unavailable for three months, what would slow down?

And you realise you are not going to enjoy answering it honestly.

That question has very little to do with your operations director. It is a test of whether the thing on offer is a business or a group of people who happen to be very good at something. Founders preparing for a sale spend months on the financial story and almost no time on the part that gets probed just as hard, which is what the business knows and where that knowledge is kept.

What a buyer is actually paying for

It helps to look at what British companies now put their money into.

The Office for National Statistics measures this directly. Investment in intangible assets was £244.7 billion in 2023, and this is £85.3 billion higher than investment in tangible assets, such as machinery and buildings, in the latest period. We have been an economy that invests more in the intangible than the physical for a while, and the gap keeps widening.

One line in that breakdown matters more than the others here. The largest uncapitalised intangible asset in 2023 was organisational capital, accounting for £42.0 billion of investment. Organisational capital is the ONS term for what a business puts into its own structures and management practices. Uncapitalised means it does not appear as an asset in the national accounts at all.

Read that twice, because it is the whole problem in one sentence. After research and software, the largest thing British business invests in is the way it runs itself, and the official measure of the economy does not carry it as an asset. Your own balance sheet does exactly the same thing. There is no line on it for the reason your pricing works.

A buyer knows this perfectly well, and it is why diligence goes where it goes.

Key person risk in due diligence is a pricing question

Sellers tend to treat key person risk in due diligence as a box somewhere between insurance and an org chart. Buyers treat it as one of the few findings in the whole process that moves the number.

An acquirer is working out what they will still own on the Monday after completion. Plant and stock are straightforward, and contracts mostly transfer subject to change of control. Customers usually stay too, at least for a while. People are the variable, and what people carry around in their heads is the most variable part of all.

That exposure is worth understanding on its own terms long before anybody is buying anything. What actually leaves when a good operator does is a longer answer than most handover plans assume, and the cost of it is the ordinary running cost of a business that keeps forgetting things it already knew. A sale process does not create that problem. It just puts a price on it, in public, in front of somebody with an incentive to find it.

The four questions your accounts cannot answer

Diligence questions about knowledge tend to arrive in plain language, which is part of why they get underestimated. Each one is testing something quite specific.

What they ask	What they are testing
If a named person were unavailable for three months, what would slow down?	Whether the work depends on a person or on a way of working
Why is that customer on those terms?	Whether pricing is a policy the business holds or a set of individual memories
What have you tried that did not work?	Whether the business records what it learns, or quietly repeats it
Where would somebody find the answer to that?	Whether the reasoning is reachable by anyone who has not been here for ten years

The third one is the question sellers handle worst, and it is the one experienced buyers care most about.

Every business of any age has a list of things it tried that failed. Markets it entered and left, a customer type it stopped chasing, a supplier arrangement that looked clever and was not. That list is expensive, because you paid for every item on it in time and money. It is also almost never written down anywhere, which means a buyer inherits the cost of learning it again. A seller who can produce that list is handing over something genuinely valuable, and demonstrating in the same movement that the business pays attention to its own history.

The fourth question is the quiet one, and it usually decides the other three. Reasoning that exists only inside the tools you rent, scattered across a CRM, a helpdesk and a few years of chat threads, is not reachable in any way a stranger can use. That is a cost you are already paying, and the bill for it arrives long before anybody is buying the business.

Why an answer you cannot evidence costs money

Here is the part that catches founders out.

In most negotiations, knowing more than the person across the table is an advantage. In diligence it runs the other way. A buyer cannot pay full value for something they are unable to verify, so when the answer to a reasonable question turns out to live in the founder's head, they have two options. They can take the seller's word for it, or they can structure the deal so the risk sits with the seller until it is proven. Their advisers exist to make sure they choose the second.

That is where deferred consideration, escrow and earn-outs come from. Those instruments are how a buyer bridges the distance between what a seller knows and what a seller can show, rather than a sign that anybody is being difficult, and the width of that gap is largely in the seller's hands. Reducing how much of the price is deferred is usually worth more to a founder than winning an argument about the multiple.

The mirror image of all this arrives after completion, when the buyer starts discovering how much of the acquired business's reasoning never made it across in the first place. It is the same asset viewed from opposite sides of one table, and neither side tends to notice it until the deal is already in motion.

The buyer may be somebody you have never met

There is a version of a sale where the acquirer is a competitor who has watched you for fifteen years, knows your market, and can fill in the gaps from experience.

A large share of UK deal value looks nothing like that. The value of inward M&A (foreign companies acquiring UK companies) was £25.4 billion during Quarter 2 2026, against £4.2 billion of domestic M&A in the same quarter. Those figures are provisional and count only transactions worth £1 million or more that changed majority share ownership, so they describe the larger end of the market rather than all of it.

The direction is the useful part. Money arriving from outside the country is attached to people with no history in your sector and no relationship with your team. They cannot extend the benefit of the doubt, because they have nothing to base any doubt on. Everything they conclude about how your business works, they conclude from what you are able to show them in a few months.

What a business that answers well looks like

A UK construction partner platform we worked with was signing up new partners faster than its team could process them, and the obvious fix was to hire. Instead the onboarding was rebuilt so the judgement inside it sat in the system rather than in whoever happened to be doing the work. It now handles more than 100 partner onboardings a month and gives back 25 hours a month, and growth stopped being a headcount conversation.

A buyer would look straight past the 25 hours. What matters to them is that growth has been decoupled from hiring, and that the rules deciding which partners get approved on what basis are written down where anybody can inspect them. That is a claim which survives a stranger checking it.

There is a reasonable standard for what written down has to mean, and it comes from an unlikely direction. The UK government's AI Playbook instructs teams running AI systems to develop a comprehensive plan for knowledge transfer, and for training new and existing staff so the system stays manageable over time. That is guidance written for public sector technology teams, and it describes exactly what an acquirer is looking for in a business of any kind. The knowledge always exists somewhere. What an acquirer is checking is whether anything has ever been done to make it survive the people currently holding it.

The lead time nobody plans for

Asked when to start, the honest answer is unwelcome.

A buyer reads history, and history cannot be backdated. Documented process affects valuation because it is evidence of how a business has actually behaved over time, and evidence accumulates at its own pace. A set of process documents written in the eight weeks before a data room opens reads, to anybody who has seen a few of these, exactly like a set of process documents written in the eight weeks before a data room opens.

Two to three years is a realistic runway, which is roughly the period a buyer will examine anyway. That sounds discouraging until you notice that none of the work is really for the sale. Recording why decisions get made the way they do reduces the load on whoever is currently carrying it, shortens the time a new starter needs to become useful, and gives back hours that were going into rediscovering settled questions. If you want a sense of the scale of that in your own business, the capacity calculator is a reasonable place to start, and the wider case for treating this as strategy rather than admin sits in what actually drives returns for UK SME leaders.

The sale is just the moment somebody else puts a price on how well you did it. Most founders would rather that moment were not the first time they found out.

Practical takeaways

• A buyer is testing whether the business's judgement is reproducible without you, and documentation is the evidence rather than the asset.
• Key person risk moves the deal structure more often than it moves the headline price, so the money usually shows up as deferred consideration rather than as a discount.
• The list of things you tried that did not work is expensive, valuable and almost never written down. Start there, because nobody else will have it.
• Anything you know but cannot show becomes the buyer's risk, and they will price it accordingly.
• Written records with no history behind them are visible as such. Two to three years is the runway, and the work pays for itself long before anybody makes an offer.

Frequently asked questions

How does a buyer assess key person risk?

By testing the business rather than reading the org chart. The questions are deliberately specific and usually sound casual, along the lines of what would slow down if a named person were unavailable for three months, or who else has held a price under pressure with a particular customer. What the buyer is measuring is the gap between how the business describes itself and how it actually runs. An org chart shows reporting lines, and reporting lines are not where the exposure sits. The exposure sits in the decisions that only one person has ever made, which is why the assessment happens in conversation with the second tier of management rather than with the owner.

Does documented process affect valuation?

It affects it through risk rather than through any direct uplift, and the effect shows up in the structure of the deal as often as in the headline figure. A buyer is being asked to pay today for performance that has to continue after the current owner stops turning up. Anything that supports the case that it will continue reduces the risk they are carrying, and anything unverifiable increases it. Documentation is not the asset itself, it is the evidence that the asset survives a change of hands. Written processes with no history behind them carry very little weight, because a buyer can tell the difference between a business that records how it works and one that produced a folder for the occasion.

What do buyers ask about how a business works?

Four things, in various forms. What happens if a specific person is not available. Why particular customers are on the terms they are on. What the business has tried that did not work. And where somebody would find the answer to any of the above without asking the owner. None of those questions can be answered from the management accounts, which is the point of asking them. They are aimed at the reasoning behind the numbers rather than the numbers themselves, because the reasoning is what has to keep working after completion.

Why does a buyer hold back part of the price?

Because they have been asked to pay now for something that can only be demonstrated later. Deferred consideration, escrow and earn-outs are not penalties or a sign of bad faith, they are how a buyer bridges the gap between what a seller knows and what a seller can evidence. The size of that gap is largely within the seller's control. A business that can show how its pricing decisions get made, why particular customers are handled the way they are, and what happens when the usual person is away, needs less of a bridge than one where those answers exist only in conversation. Reducing the amount of the price that is deferred is usually worth more than arguing about the multiple.

How long before a sale should you start?

Longer than feels reasonable, because a buyer reads history and history cannot be backdated. Two to three years is a realistic runway for the evidence to look like a record rather than an exercise, which is roughly the period a buyer will examine anyway. The better framing is that none of this work is done for the sale. Writing down why decisions get made the way they do reduces the load on the people carrying it, shortens how long a new starter takes to become useful, and makes the business easier to run whether or not anybody ever buys it. The sale is simply the moment somebody else puts a price on how well you did it.