There's a specific fear that arrives for founders in the weeks after they accept an offer. The deal is agreed in principle. The signing feels close. And then their advisor mentions that due diligence is starting next week, and the founder realises they don't actually know what that means.
They know it's important. They know deals die in it. They've heard horror stories from friends. But if you ask them what a buyer's diligence team will actually do, day by day, over the six to twelve weeks that follow, most founders can't tell you. Which means they can't prepare for it, and can't tell whether the process is going well or badly until it's over.
The fear, in our experience, is usually worse than the reality. Diligence is structured, predictable, and — done properly — mostly a matter of producing documents that already exist. The founders who dread it most are usually the ones who haven't been shown what it actually is. So this piece is that: a plain walkthrough of what buyers actually do, in what order, and what they're looking for at each stage.
An X thread from a mid-market operator described the founder side of it well:
Every seller thinks diligence is an audit designed to lower the price. It isn't. It's the buyer's team confirming that what you told them is true. If it is, the process is uneventful. If it isn't, the process is how they find out.
— X, sell-side advisory commentary
That distinction matters. Diligence isn't hostile; it's confirmatory. The buyer has already decided they want the business — they wouldn't be spending six figures on their diligence team otherwise. What they're doing now is making sure the business they're buying is the one you described.
The shape of a diligence process
A typical diligence process for a small-to-mid-sized business runs six to twelve weeks between LOI signing and definitive agreement. In that window, the buyer will deploy several parallel workstreams, each led by a specialist, each looking at a different dimension of the business.
You'll interact with all of them, usually through your advisor as intermediary, and each will produce a list of requests, questions, and follow-ups. The requests can feel overwhelming in the first week — a hundred and fifty document requests is not unusual — but the volume settles quickly once the initial data room is populated.
The workstreams typically run in the following rough order, though they overlap significantly.
Financial diligence
Almost always the first workstream to start, and often the one that determines whether the rest of the process proceeds at all. The buyer's accountants or a specialist quality-of-earnings (QoE) firm will spend three to six weeks examining your financials in depth.
They're looking for a few specific things.
Are the reported earnings real? They'll reconcile your management accounts to your tax filings, examine your revenue recognition policies, test a sample of transactions against source documents, and look for any patterns that suggest the earnings are overstated. Common issues: revenue booked before it's earned, related-party transactions that inflate the top line, one-off items presented as recurring.
Are the adjustments defensible? Every set of adjusted earnings — the “EBITDA add-backs” the founder used to arrive at the number in the IM — will be examined line by line. Legitimate add-backs (a founder salary above market, one-time legal costs, personal expenses run through the business) will be accepted. Illegitimate ones will be challenged, and each challenge that lands reduces the effective EBITDA the buyer is willing to pay a multiple on.
What's the quality of the revenue? Recurring vs. one-off, customer concentration, contract length, gross margin trend, churn if it applies. Two businesses with the same EBITDA can be worth very different multiples based on the answers here.
Is the working capital normal? The buyer will want the business delivered with a “normalised” level of working capital — enough to operate without an immediate cash injection. Disputes about what “normal” means here can shift the purchase price by meaningful amounts.
Financial diligence is the workstream most likely to produce a price adjustment. The founders who come through it cleanly are the ones whose adjustments were honest at the start and whose books support the numbers in detail. The founders who watch their price drop by 10 to 20% in diligence are usually the ones who padded the adjustments and got caught.
Legal diligence
Runs alongside financial diligence, typically for four to eight weeks. The buyer's lawyers will examine every material contract, corporate document, and legal exposure.
The categories are relatively standard.
Corporate. Your incorporation documents, share register, shareholder resolutions, board minutes, corporate structure. They'll want to confirm that your ownership is what you say it is, and that no historical corporate action has left a lingering claim on the equity.
Material contracts. Customer contracts, supplier contracts, distribution agreements, partnership agreements, franchise agreements — anything that's material to the business. They'll examine the terms, the assignability, the change-of-control provisions, and the risk of any party terminating or repricing on the transaction.
Employment. Employment contracts for all staff, particularly key personnel. Non-compete and non-solicitation clauses. Any pending or historical employment disputes. In some jurisdictions, statutory obligations that survive the sale.
Intellectual property. Trademarks, patents, copyrights, software ownership. Critically, they'll want confirmation that any IP the business relies on is actually owned by the business, not by the founder personally or by contractors who never signed proper assignments.
Regulatory and licences. Any licences, permits, or regulatory approvals the business requires, and whether they transfer on a sale.
Litigation. Any current, pending, or threatened legal actions.
Real estate. Leases for any premises, terms, renewal options, assignability.
The most common failure mode here is missing documents. Founders who don't have their material contracts in one place, or who can't produce a clean cap table, or who never got proper IP assignments from early contractors, discover these gaps under time pressure — and often can't fix them fast enough to hold the deal.
Commercial diligence
Less standardised than financial or legal, but common on any serious deal. The buyer wants to test the business's story about its market position, growth prospects, and competitive dynamics.
They'll typically do some combination of the following: call a sample of your customers, call a sample of your former customers, interview industry participants, benchmark your metrics against comparable businesses, and test the assumptions in your growth projections.
The customer calls are the part founders worry about most, and often unnecessarily. Buyers do these carefully — through neutral references, without disclosing the transaction, framed as generic market research or supplier feedback. The purpose isn't to alarm your customers; it's to hear from them, unfiltered, what they think of your business, your product, your service, and the likelihood they'd continue as customers under new ownership.
The customer-call findings can move the price significantly in either direction. Strong customer feedback strengthens the buyer's conviction and can lead to firmer terms. Weak feedback — a concentrated customer expressing hesitation about the transaction, or a general pattern of dissatisfaction — can trigger renegotiation.
The founders who come through commercial diligence well tend to have a defensible story about the business — realistic growth projections rather than hockey sticks, clear-eyed acknowledgement of the competitive dynamics, and enough humility about the risks that the buyer doesn't feel they need to discover them independently.
Tax diligence
Often folded into financial diligence, sometimes run separately. The buyer's tax advisors will examine your historical tax positions, filings, and exposures.
They're looking for: unpaid or underpaid taxes from prior years, aggressive positions that might be challenged by revenue authorities, transfer-pricing exposures in cross-border businesses, and the tax implications of the transaction structure itself.
Tax diligence is worth taking seriously because tax findings can be structured into the deal — through indemnities, escrows, or purchase price adjustments — but they slow the process meaningfully and can produce material dollar consequences. Founders who've been operating close to the edge on tax positions often discover the cost of that during diligence.
Operational and technology diligence
Depending on the business, the buyer may run additional workstreams examining operations, systems, and technology.
Operational. How does the business actually function day-to-day? What are the key processes, who executes them, what happens if key people leave? For businesses with physical operations — manufacturing, logistics, hospitality — this can involve site visits and operational audits.
Technology and IT. If the business relies on proprietary software or a specific technology stack, the buyer's technical team will examine it. Code quality if there's proprietary code, security posture, vendor dependencies, scalability. This can be light or heavy depending on how tech-dependent the business is.
HR and people. For businesses where the team is critical, the buyer may want to meet key employees under NDA, understand the retention risks, and assess whether the culture will survive the transition.
Each of these workstreams produces its own document requests, meetings, and follow-ups.
The specific things buyers look for
Across all workstreams, buyers are looking for a few specific categories of finding.
Confirmations. The best outcome for the buyer, from a process point of view, is that everything you told them checks out. Most diligence findings are confirmations, and they're what allows the process to proceed to signing.
Small issues. Nearly every business has some. A missing IP assignment from a former contractor, a minor tax exposure, a customer contract with an awkward change-of-control clause. These get catalogued, priced, and typically resolved through warranties, indemnities, or small price adjustments.
Material issues. Larger problems that materially affect the value or the risk profile of the business. Overstated adjusted earnings, a significant customer preparing to leave, a serious legal exposure, an IP dispute. These trigger real renegotiation — a price reduction, a restructured earn-out, additional escrows, or in the worst case, the buyer walking away.
Deal-breakers. Findings so serious they end the transaction outright. Systematic misrepresentation in the financials, undisclosed litigation of significant scale, fundamental issues with the ownership of the business. These are rare when the founder has been honest, and much more common when they haven't.
The distinction between these categories matters, because founders often panic at the first indication of any finding and assume the deal is dying. Most findings are small. Only a small percentage of findings are deal-breaking. The difference between how a founder handles the first two categories often determines whether they escalate into the third.
The seller's job during diligence
The founder's role during diligence is more specific than most realise. It isn't just to answer questions. It's to be a particular kind of counterparty for six to twelve weeks.
Responsive. Every diligence request should be acknowledged within a business day, and answered — or explicitly triaged with a delivery date — within a few days. The buyers' team is running on a schedule, and their perception of the deal degrades quickly when the responses slow down.
Complete. When you send a document, send the whole document. Partial deliveries create follow-up requests, which create the impression that information is being managed rather than shared. Full, clean deliveries build trust.
Honest. This is where the previous pieces in this series come back into play. If you overstated the earnings, if you glossed over the customer concentration, if you presented a happy story about the growth trend — diligence is where those choices become visible. The founders who handle diligence well are the ones who told the truth in the IM. The founders who struggle in diligence are usually the ones now trying to defend claims that were exaggerated to begin with.
Composed. Diligence will surface things you'd rather it hadn't. A customer whose satisfaction is lower than you thought. A tax position that's more exposed than you realised. A contract clause you'd forgotten about. Your response to these findings, in real time, is being watched. Founders who respond defensively — “that's not fair,” “the buyer doesn't understand” — signal that they're going to be difficult to deal with post-closing, which makes buyers more cautious. Founders who respond with “let me look into that and get back to you” preserve the buyer's confidence.
How to be ready before diligence starts
The most important thing to know about diligence is that most of the work of surviving it happens before it starts.
The founders who come through diligence cleanly have, in the twelve to twenty-four months before it began, done the following:
Their books have been cleaned up to the point where a stranger could read them. The adjustments have been made honestly and could survive scrutiny. Material contracts have been located, reviewed, and organised. IP has been properly assigned. Employment contracts are in place for all key staff. Tax positions have been reviewed with a competent advisor. Any known issues — the customer concentration, the aggressive tax position, the missing IP assignment — have been either fixed or documented so they can be disclosed cleanly rather than discovered.
None of this is glamorous. It's the same work we've written about in every other piece in this series — the two to three years of preparation that separates the founders who exit well from the ones who don't. Diligence is where that preparation gets tested. Founders who did it, breeze through. Founders who didn't, spend six weeks scrambling and often watch the price drop or the deal die.
The uncomfortable read
If you're within a year of a possible sale, the useful exercise isn't dreading diligence in the abstract. It's imagining it specifically.
If a buyer's team asked you today for the last three years of monthly management accounts, reconciled to your tax filings — could you produce them within a week? If they asked for every material customer contract, with amendments and current status — could you produce them in one clean pack? If they asked to see the IP assignments from every contractor who ever wrote code for you — do those exist?
The gaps in your honest answers to those questions are the gaps in your readiness. Each one that exists today will still exist when the buyer asks about it, but by then it will be too late to fix — the request itself will make the gap visible. Every gap you close now is a diligence finding that doesn't happen later.
The founders who dread diligence are the ones with unaddressed gaps. The founders who don't have prepared. The distance between those two states is entirely within your control, but only if you start on it before the buyer's team is on the phone.
If you'd like a candid read on how ready your business would actually be if diligence started tomorrow — where the gaps are, what's fixable in the time you have, and what would need to be disclosed — a private conversation is the fastest way to find out. Book a private consultation and we'll walk through it with you honestly.
A note on the sources
The observations in this piece draw on public discussions across r/SellMyBusiness, r/smallbusiness, and r/Entrepreneur, X threads from lower-middle-market M&A operators, and PaperToaster's own advisory work. Quotes are lightly edited for length.