FOR SELLERS
Due Diligence Explained: What Buyers Will Ask For (and How to Be Ready)
Due diligence is where deals fall apart
Here's what buyers will ask for and how to have everything ready before they ask.
Signing a Letter of Intent feels like the finish line. It isn’t. It’s the starting gun for the phase of a sale where most of the real work, and most of the risk, actually happens. Due diligence is the buyer’s formal investigation of your business: a systematic effort to verify that everything you and your broker represented is true, documented, and defensible.
Sellers who understand what’s coming and prepare for it move through this phase in weeks. Sellers who don’t spend those same weeks scrambling — and give buyers every reason to renegotiate price or walk away entirely.
I. What Buyers Are Actually Verifying
Due diligence isn’t buyers being difficult. It’s buyers (and, in most deals, their lenders) confirming that the story told in your financials and your CIM holds up under scrutiny. Every number, every contract, every claim about how the business runs gets checked against the underlying paper trail.
That means the burden of proof shifts. During marketing, you were telling your story. During diligence, buyers are testing it — and any gap between what was said and what the documents show becomes a negotiating point, or worse, a reason to walk.
II. The Document Requests You Should Expect
Customer data
- Customer concentration (what share of revenue sits with your largest accounts)
- Contract terms and renewal/retention history
| Category | What buyers ask for | Why it matters |
|---|---|---|
| Financial | 3 years tax returns, reconciled P&Ls, bank statements, AR/AP aging | Confirms the earnings buyers are pricing are real and repeatable |
| Legal | Leases, contracts, licenses, litigation history | Surfaces anything that could complicate or block a transfer |
| Operational | Org chart, SOPs, payroll, key-employee terms | Tests whether the business runs without you, not just with you |
| Customer | Concentration %, contract terms, retention | Prices the risk of losing revenue post-close |
Legal and contractual
- Corporate formation documents and cap table
- Lease agreements and any assignment/consent provisions
- Material customer and vendor contracts
- Licenses, permits, and litigation history
Operational and employee
- Org chart and employee census
- Payroll records and any key-employee agreements
- Documented systems, processes, or SOPs the business runs on
III. What's Different About Due Diligence Right Now
The mechanics above haven’t changed much in years. What has changed is how thorough and how long this phase has gotten, and a few new categories buyers are actively screening for.
Industry-wide reporting on 2026 deal activity shows pre-close diligence timelines have stretched well beyond where they sat even five years ago, with buyers now routinely running parallel workstreams — financial, legal, operational, customer, and increasingly technology and AI exposure — rather than working through a single sequential checklist. That last one is new: buyers are starting to ask how much of a business’s revenue or day-to-day operation depends on tasks that AI tools could plausibly automate or disrupt in the next few years. It’s not a dealbreaker on its own, but it’s now a real question in the room, and sellers who haven’t thought about it are caught flat-footed.
Quality of Earnings (QoE) reviews, once mostly a middle-market tool, have become standard practice on much smaller deals too, largely because they routinely catch add-back adjustments that materially change the number a buyer is willing to pay.
On the financing side, SBA lending changes taking effect in 2026 are pulling more transactions into SBA’s documentation standards — including a faster electronic tax-transcript verification process replacing the old paper-based request. For sellers, the practical effect is the same either way: whether your buyer is paying cash or using SBA financing, the depth of financial documentation expected has gone up, not down.
IV. How to Be Ready Before They Ask
The businesses that move through this phase quickly aren’t necessarily the cleanest operations, they’re the ones that got organized before they needed to be.
- Reconcile three years of financials before you ever go to market, not after a buyer asks
- Build a data room proactively: leases, contracts, licenses, and payroll records assembled in one place
- Know your customer concentration number cold, and have a plan to address it if it’s high
- Document and be ready to defend every add-back with paper, not just an explanation
- Write down the systems and processes that run the business, so continuity doesn’t rest entirely on your word
Conclusion: Preparation Turns Diligence From a Threat Into Proof
The work happens before diligence starts, not during it. If you’re planning to sell in the next 12–24 months, the organizing you do now is what determines whether this phase takes three weeks or three months.
Not Sure If Your Business Is Diligence-Ready?
Get a clear-eyed view of what a buyer will actually ask for, and what to shore up before they do.