A due diligence checklist for founders should cover six core categories: financial, legal, tax, technical, commercial, and HR documentation. These categories give investors or buyers a complete picture of your business before committing to a deal. The sections below break down each area in detail, from what documents belong in your data room to the red flags that can derail a transaction.
What documents go on a due diligence checklist?
A due diligence checklist typically includes documents across six categories: financial records, legal agreements, tax filings, technical assets, commercial contracts, and HR documentation. Each category addresses a different dimension of business risk, and investors or buyers will expect comprehensive coverage of all six before closing a deal.
Financial documents
Financial due diligence covers the numbers that tell the story of your business’s health. Expect to provide audited annual accounts, monthly management reports, cash flow statements, budget forecasts, and details of any outstanding debt or liabilities. Investors want to verify that the figures in your pitch deck match the reality in your books.
Legal, tax, technical, commercial, and HR documents
Beyond the financials, your checklist should include:
- Legal: Articles of association, shareholder agreements, cap table, any ongoing litigation or disputes
- Tax: Corporate income tax filings, VAT and payroll tax returns, any approved tax rulings or R&D incentives such as the innovation box
- Technical: Software documentation, patents, trademarks, and intellectual property ownership records
- Commercial: Key customer contracts, supplier agreements, and an overview of revenue concentration
- HR: Employment contracts, organizational chart, pension scheme details, and any outstanding disputes with employees
The more complete and current these documents are before a process starts, the faster and smoother the investigation will be.
What’s the difference between financial and legal due diligence?
Financial due diligence examines the economic performance and health of a business, revenues, costs, cash flow, margins, and forecasts. Legal due diligence examines the legal structure and obligations of the business, contracts, corporate governance, compliance, and litigation risk. Both are essential, but they answer different questions for an investor or buyer.
Think of it this way: financial due diligence tells you whether a business is profitable and sustainable. Legal due diligence tells you whether there are hidden obligations, disputes, or structural issues that could affect the deal or create liability after closing. In practice, they often run in parallel, led by different advisors, but the findings feed into a single risk assessment.
For founders, the distinction matters because the documents you need to prepare are different. Financial due diligence requires your CFO or finance team to lead. Legal due diligence requires your legal counsel to review and organize corporate records, contracts, and compliance documentation. Starting both workstreams early gives you the best chance of a clean process.
How long does a due diligence process typically take?
A due diligence process typically takes four to twelve weeks, depending on the complexity of the business, the type of transaction, and how well prepared the seller is. Simpler transactions at early-stage companies can move faster. Larger acquisitions or businesses with complex structures, multiple entities, or international operations often take longer.
The single biggest variable within your control is preparation. Founders who have a structured, up-to-date data room ready before the process begins can compress the timeline significantly. When investors or buyers submit a request list and documents are already organized and dated, the back-and-forth that typically slows things down is largely eliminated.
Delays most often occur when documents are missing, outdated, or scattered across different systems. A request that should take a day to fulfill can stretch into weeks if your finance team has to reconstruct records or track down approvals. Proactive preparation is the most effective way to stay in control of the timeline.
What do investors look for during due diligence on a startup?
During due diligence on a startup, investors primarily look for validation that the business is what it appears to be, and for risks that were not disclosed upfront. They focus on revenue quality, cash flow sustainability, legal ownership of key assets, team stability, and whether the financial projections are grounded in reality.
More specifically, investors pay close attention to:
- Revenue concentration: Is the business overly dependent on one or two customers? What happens if they leave?
- Intellectual property ownership: Does the company actually own its technology, or are there gaps in IP assignment?
- Cap table clarity: Is the ownership structure clean, or are there unresolved founder disputes, convertible notes, or option pools that complicate things?
- Burn rate and runway: How long can the business operate without additional capital?
- Compliance: Are tax filings current? Are employment contracts in order? Are there any regulatory issues?
Investors are not just looking for problems. They are also building confidence. A startup that presents organized, complete documentation signals that the management team is in control and can be trusted to run the business after the investment closes.
How should founders prepare a data room for due diligence?
Founders should prepare a data room by organizing all relevant documents into clearly labeled categories, using software they already work with such as Microsoft SharePoint or Google Drive, and keeping every document consistently dated. The goal is to create a single, structured source of truth that any investor or advisor can navigate without hand-holding.
A practical structure for your data room looks like this:
- Financial: Annual accounts, management reports, forecasts, bank statements
- Legal: Corporate documents, shareholder agreements, contracts
- Tax: Tax filings, rulings, VAT and payroll records
- Technical: IP documentation, software records, patents
- Commercial: Customer contracts, supplier agreements, pipeline data
- HR: Employment contracts, org chart, pension information
The CFO plays a central role here. Keeping the data room continuously updated, not just when a deal is on the table, means that when a real process begins, the first checkboxes are already green. This builds immediate confidence with investors and buyers, and it strengthens your negotiating position because you are not scrambling to fill gaps under time pressure.
Date every document. Investors need to know they are looking at the most current version. An undated document creates doubt, even if the content is accurate.
What are the most common due diligence red flags for founders?
The most common due diligence red flags include revenue that cannot be verified, missing or unsigned contracts, unclear IP ownership, unresolved legal disputes, inconsistencies between financial statements and management reports, and a cap table that does not reflect the actual ownership structure. Any of these can slow a deal, reduce valuation, or cause an investor to walk away.
Here are the red flags that surface most frequently:
- Revenue concentration: More than 30 to 40 percent of revenue from a single customer is a significant risk factor
- Undocumented agreements: Verbal commitments or informal arrangements that are not reflected in signed contracts
- IP gaps: Code or technology developed by contractors or co-founders without proper IP assignment agreements
- Tax arrears or unresolved filings: Missing returns or outstanding disputes with tax authorities
- Inconsistent financial data: Numbers that differ between pitch materials, management accounts, and statutory filings
- HR issues: Misclassified workers, missing employment contracts, or pension obligations that are not properly accounted for
Most red flags are not deal-breakers on their own. What matters is how founders respond to them. Acknowledging an issue proactively and presenting a clear resolution plan is far better than having an investor discover it during the investigation. Transparency builds trust. Surprises destroy it.
How Greyt helps with due diligence
We guide founders, CFOs, and investors through the full due diligence process from a CFO perspective, focused on clarity, risk reduction, and protecting value at every stage of a transaction. Our approach is structured, practical, and built around your specific situation.
Depending on where you are in the process, we can support you with:
- Finance Maturity Assessment (FMA): A thorough review of your financial organization, processes, systems, and reporting, delivered as a concrete set of recommendations before any transaction begins
- Acquisition due diligence: A detailed investigation of a target company’s financials, cash flow, debt, profitability, and compliance, so you can make informed decisions and avoid hidden risks
- Refinancing due diligence: An assessment of financial health and long-term sustainability to support better terms with lenders
- Data room preparation: Hands-on support to structure, populate, and maintain your virtual data room so you enter any process from a position of strength
Our team of experienced interim CFO expert services has guided companies through funding rounds, exits, and acquisitions across a wide range of sectors. We deliver clear, actionable reports, not lengthy documents that sit on a shelf. If you are preparing for a transaction or want to get your financial house in order before one arrives, get in touch with us and let us help you move forward with confidence.
Frequently Asked Questions
Should I prepare a due diligence checklist even if I'm not actively fundraising or selling?
Yes, absolutely. Maintaining a due diligence-ready data room as a standard business practice means you are never caught off guard when an opportunity or offer arrives unexpectedly. It also has operational benefits: clean financial records, up-to-date contracts, and organized HR documentation make your business easier to manage day-to-day. Think of it as financial hygiene rather than a one-time transaction task.
What's the best way to handle a red flag that surfaces during due diligence?
The most effective approach is to disclose it proactively and come prepared with a resolution plan. Investors and buyers expect to find imperfections — what they are really evaluating is how the management team responds to problems. A founder who surfaces an issue early, explains the context, and outlines concrete steps to resolve it builds far more trust than one who lets the same issue be discovered by an external advisor during the investigation.
How do I know if my cap table is clean enough for due diligence?
A clean cap table clearly reflects every shareholder, option holder, and convertible note holder, with no ambiguity about ownership percentages or rights. Common issues include unresolved agreements with early co-founders, undocumented informal equity promises, or option pools that haven't been formally approved. Have your legal counsel review the cap table before any process begins and reconcile it against your articles of association and any shareholder agreements.
What tools or software should I use to set up a virtual data room?
For early-stage companies, well-organized shared drives using tools you already use — such as Google Drive or Microsoft SharePoint — are often sufficient and immediately accessible to investors. For larger transactions or where document-level access control and audit trails are important, dedicated virtual data room platforms such as Datasite, Intralinks, or Ansarada offer more robust features. The most important factor is not the tool itself, but the consistency of your folder structure, file naming, and document dating.
Can due diligence affect the final valuation of my company?
Yes, significantly. Due diligence findings directly influence how investors or buyers assess risk, and risk adjustments translate into valuation. Unresolved red flags — such as revenue concentration, IP gaps, or tax arrears — can result in price reductions, earn-out structures, or additional representations and warranties that shift risk back to the seller. Conversely, a clean, well-prepared data room can strengthen your negotiating position and support the valuation you presented during early discussions.
Who should own the due diligence process on the founder's side?
The CFO or Head of Finance should take the lead on coordinating the overall process, with clear ownership assigned for each category: legal counsel for corporate and contract documents, the finance team for financial and tax records, HR for employment documentation, and the CTO or engineering lead for technical and IP records. Without a single coordinator driving the process, requests fall through the cracks and timelines slip. If your company doesn't have a CFO in place, bringing in an interim CFO or contact an external advisor before the process begins is a practical solution.
What's the difference between buy-side and sell-side due diligence, and does it change what I need to prepare?
Sell-side due diligence is conducted by the company being sold or invested in — you are preparing and presenting your own documentation for scrutiny. Buy-side due diligence is conducted by the investor or acquirer investigating a target. As a founder going through a funding round or exit, you are primarily on the sell side, which means your job is to organize, verify, and present your documentation as clearly and completely as possible. Some founders also commission a vendor due diligence report — an independent review of their own business — to get ahead of likely findings and present a credible, pre-validated picture to buyers.