Due Diligence Checklist

Diligence exists to disconfirm the thesis, not confirm it: find the reason not to invest before the money moves. The costly mistake it prevents is confirmation bias - founders are persuasive, decks are polished, and the investor who only looks for supporting evidence reliably finds it. Enter assuming the deal is flawed and go hunting for the flaw; diligence is where skepticism is earned.

Operating procedure

Run the four workstreams in this order. Commercial comes first because a broken market thesis makes the other three moot; legal comes last because its landmines are cheapest to check once the deal still looks alive.

Step 1: Gather inputs

Collect before starting, and label every unverified founder claim as a claim:

1. The written investment thesis - one paragraph stating why this deal wins. Every finding gets tied back to it.
2. The data room or document set: financials, bank statements, cap table, material contracts, customer list.
3. Access for 3-5 customer reference calls (default: the investor picks the names, not the founder).
4. Deal type and check size - depth should scale with the check; a small angel check gets the killer questions, not all four workstreams at full depth.
5. Timeline and any exclusivity clock already running.

Step 2: Commercial diligence - the market and the right to win

• Market: validate the TAM bottom-up (route to market-sizing), confirm the growth rate, and pressure-test timing - why now.
• Customers: talk to real ones. Why did they buy, would they recommend it, what would make them leave? Reference calls are the single most informative step in all of diligence; never skip them.
• Competition: who else solves this, and specifically why this company wins.
• Moat: what protects the business as it scales (route to competitive-moat).
• Unit economics: CAC, LTV, and payback validated from raw data, never from the deck.

Step 3: Financial diligence - the numbers behind the story

• Reconcile reported revenue to bank statements and signed contracts. Confirm it is real, recurring, and recognized correctly. Revenue that will not reconcile to cash is a deal-killer, full stop.
• Quality of revenue: customer concentration (flag any single account above ~25% of revenue), churn, contract length, one-time versus recurring mix.
• Burn rate and runway from the actual cash position, not the model.
• Forecast assumptions: grounded in pipeline and cohort history, or aspirational?
• Cap table: ownership, option pool size, any unusual preferences or convertible debt.

Step 4: Technical diligence - for technology targets

• Architecture scalability and the single largest technical risk.
• Code and infrastructure health; tech debt that will slow the stated roadmap.
• Security and data-handling posture; compliance exposure on privacy and regulated data.
• Engineering depth and key-person risk - if one departure halts the roadmap, price that in.
• IP ownership: confirm all code is assigned to the company.

Step 5: Legal diligence - the structural landmines

• Clean incorporation and a cap table that matches the company's records.
• IP assignments signed by every founder, employee, and contractor - this is a frequent gap and can sink a deal on its own.
• Material contracts and any change-of-control clauses that fire on this transaction.
• Litigation, regulatory issues, outstanding liabilities.
• Employment compliance and any live or historical co-founder disputes.

Step 6: Synthesize

Score each workstream pass / concern / fail. List every red flag and sort each into exactly one of two buckets:

• Deal-killers: fraud, revenue that will not reconcile, broken or contested cap table, unsigned IP with an uncooperative counterparty, no real moat in a commodity market.
• Manageable risks: fixable with a closing condition, a board covenant, an escrow/holdback, or a priced-in discount.

If a red flag cannot be confidently placed in either bucket, treat it as a deal-killer until resolved. Then answer the only question that matters: does the original thesis still hold?

Red-flag register template

DILIGENCE RED-FLAG REGISTER - [FILL: target] - thesis: [FILL: one line]

#  WORKSTREAM   FINDING                          EVIDENCE            BUCKET        REMEDY / CONDITION
1  [FILL]       [FILL]                           [FILL: doc/call]    Deal-killer   n/a - walk unless resolved
2  [FILL]       [FILL]                           [FILL]              Manageable    [FILL: covenant/escrow/condition]
...

VERDICT: GO / GO WITH CONDITIONS / NO-GO
Thesis status: HOLDS / HOLDS WITH REVISION / BROKEN - [FILL: one sentence why]

Worked lines: "Financial - $310k of reported ARR is a signed LOI, not a contract - bank recs + contract review - Deal-killer unless converted to signed contract before close." "Legal - two early contractors never signed IP assignment - assignment audit - Manageable: closing condition that both sign before wire."

Deliverable

Produce a diligence report containing: findings by workstream with a pass/concern/fail score, the red-flag register split into deal-killers versus manageable risks (each manageable risk paired with its remedy), the validated unit economics, and a go / no-go recommendation tied explicitly back to the original investment thesis.

Do NOT

• Do not take deck numbers as findings; every material number must reconcile to a primary source (bank statement, contract, raw data).
• Do not let the founder curate the customer reference list - hand-picked references are a screened sample.
• Do not treat evasion as noise. When a founder is evasive on a specific topic, follow the evasion; it is the highest-signal thread in the deal.
• Do not blend deal-killers and manageable risks into one undifferentiated "risks" list - the whole decision rides on that split.
• Do not keep diligencing to justify sunk effort after a deal-killer is confirmed; the correct output of good diligence is often no-go.

Quality bar

The report ships only when: every red flag cites its evidence source; every manageable risk has a named remedy; unit economics were rebuilt from raw data; at least three customer references were spoken to (or the gap is flagged prominently); and the recommendation explicitly states whether the thesis holds.

Escalation

This is not legal, tax, or investment advice. Bring in transaction counsel for legal diligence and a QoE (quality of earnings) firm for financial diligence on any deal large enough to warrant the fee. For understanding the term sheet the deal produces, route to term-sheet-explainer; for negotiating it, term-sheet-negotiation.