A due diligence in a VC funding round covers four workstreams: financial, legal, tax and commercial. Realistic preparation takes ten to twelve weeks if the data room starts from zero. Founders who only begin once the term sheet is on the table lose time, lose negotiation leverage and, in several cases I have seen, lose the entire round. The sections below show what investors systematically assess in each workstream and how to prepare for it without scrambling.
Financial due diligence: the numbers behind the numbers
Financial DD goes far beyond the annual financial statements. Investors want to understand how the numbers are built, whether they are reliable and what they say about the future.
Mandatory documents for the data room
- Annual financial statements for the last three years (HGB) including notes and management report
- Monthly management accounts (BWA) for the last twelve months
- Current trial balance (Summen- und Saldenliste)
- Three-statement financial model (P&L, balance sheet, cash flow) with planning assumptions
- Cap table with all shareholdings, VSOP pools and convertible loans
- Overview of existing financing instruments (loans, convertible notes, grants, KfW programmes)
- Receivables list with ageing structure and default history
- Revenue breakdown by customer, product and region
What investors look at most closely
- Revenue quality: One-off effects vs. recurring revenue. Investors want to understand which share of revenue is contractually secured or structurally recurring — regardless of whether the model runs on subscriptions, project work or service contracts.
- Unit economics: Customer acquisition cost (CAC), lifetime value (LTV), payback period. If these numbers are not cleanly available, it signals a lack of finance maturity.
- Cash conversion: How quickly does revenue turn into cash? Long receivables cycles or negative working capital dynamics are red flags.
- Consistency of planning assumptions: Does the financial model align with historical performance? Assumptions that break with the past need exceptional justification.
Legal due diligence: corporate law and IP
Legal DD examines whether the company is set up cleanly from a legal perspective and whether the ownership structure can withstand an investment.
Mandatory documents for the data room
- Current articles of association (Satzung) including all amendments
- Current commercial register extract (Handelsregisterauszug)
- Shareholder list and shareholder resolutions
- Existing investment agreements and shareholders' agreements
- VSOP/ESOP programmes with all related agreements
- Material customer contracts (top 10 by revenue)
- Supplier contracts with dependency risk
- IP registrations: patents, trademarks, domains
- Employment contracts of management and key employees
- Pending or threatened litigation
- IP assignment agreements for all external developers and freelancers, regardless of their country of origin
What consistently surfaces in legal DD
- The IP chain traced back to its origin: German copyright law leaves rights with the creator until they are transferred by contract. The Employee Inventions Act applies to employees only, not to freelancers. If the company used external developers early on without an IP assignment clause in their contracts, that gap is hard to close retrospectively. It applies equally to the developer in Germany and the one in Ukraine or India. Investors want to see an unbroken chain of title for every material IP asset. A missing link means a condition in the term sheet or a valuation discount.
Tax due diligence: German specifics
Tax DD carries particular weight in Germany because the regulatory complexity is higher than in many other startup ecosystems.
Mandatory documents for the data room
- Tax assessments and audit reports for the last three to five years
- GoBD compliance: process documentation for all bookkeeping-relevant IT systems
- E-invoicing compliance: receipt capability (mandatory since 2025), issuance obligation (from 2027 for companies above 800,000 EUR revenue)
- Loss carry-forwards: balance, usability and risks from share transfers (§ 8c KStG)
What consistently surfaces in tax DD
- Share transfers below market value: Shares transferred to co-founders or key people at nominal value after a valuation round can be reclassified as employment income if the tax authorities see a link to services rendered for the company. The difference between transfer price and fair market value becomes a taxable benefit in kind. Wage tax and social security liability falls on the company. Investors ask about every share transfer from the founding period and want to see the valuation basis documented.
- Permanent establishment through founders working abroad: The OECD commentary update of November 2025 brought clarity for mobile employees. For founders with an operational management role that clarity does not extend in the same way, because the place of effective management is what counts. A CEO signing contracts, making decisions and chairing board meetings from Spain can create tax nexus abroad. Investors check travel patterns, governance protocols and whether management decisions are documented as taking place in Germany.
The tax details, from VAT cut-off to transfer pricing documentation, belong with your tax advisor. From a CFO perspective, what matters is that the tax documentation is complete and structured in the data room before the investor asks.
Commercial due diligence: market and business model
Commercial DD assesses market position and the scalability of the business model. It is less document-driven and more analysis and interview based.
- Market analysis: total addressable market (TAM), serviceable addressable market (SAM), serviceable obtainable market (SOM)
- Competitive analysis with clear positioning
- Customer structure: concentration risk (top 5 customers as a share of total revenue)
- Pipeline overview with conversion rates and average deal size
- Churn analysis (for SaaS/subscription models): logo churn, revenue churn, net revenue retention
- Reference customers for investor calls (with prior alignment)
The role of the fractional CFO in DD preparation
Due diligence is the moment when it becomes visible whether a company's finance structures hold. A fractional CFO prepares this moment long before the investor opens the data room:
- Financial model and equity story: The three-statement model not only has to be correct mathematically. It needs to tell a consistent story. Investors check whether planning assumptions match historical performance. An experienced CFO builds the model so that it withstands questions.
- Data room structure and completeness: Folder structure, naming, version control. These are the details that professional investors immediately read. A fractional CFO knows the expectations from experience and builds the data room the way investors expect to see it.
- KPI reporting and unit economics: CAC, LTV, payback period, net revenue retention. These numbers must not only exist. They have to be consistent, traceable and trackable across multiple months. That is build-up work that begins months before the DD.
- Coordination with tax advisor and lawyer: The CFO orchestrates the process, the tax advisor delivers tax documentation, the lawyer the legal side. Without someone holding the full picture, gaps emerge between disciplines.
- Internal mini-DD: The most valuable step is running your own due diligence before the investor does. What questions would a critical examiner ask? Where are documents missing? Where are the numbers inconsistent? A fractional CFO brings the outside perspective founders need at this stage.
The most expensive due diligence mistakes do not happen during the DD. They happen in the months before. A financial model built under time pressure, a cap table that only gets cleaned up during the process, reporting that has to be set up from scratch for the investor. All of that costs time, valuation points and negotiating power. DD preparation begins on the day you decide to raise.
The 12-week preparation timeline
The best due diligence is the one that produces no surprises. Founders who start twelve weeks before the expected DD can close structural gaps without explaining them under time pressure.
| Week | Focus | Outcome |
|---|---|---|
| 1–2 | Set up data room, build document list | Structured data room with folder hierarchy |
| 3–4 | Financial documents: BWAs, annual statements, financial model | All core financial documents complete |
| 5–6 | Legal documents: contracts, IP, corporate law | All legal documents reviewed and complete |
| 7–8 | Tax compliance: GoBD, e-invoicing, tax assessments | Tax documentation complete |
| 9–10 | Commercial: market analysis, pipeline, reference customers | Commercial data foundation in place |
| 11–12 | Internal mini-DD: dry run through investor lens | All open questions identified and closed |
FAQ
How do I prepare for a VC due diligence?+
Preparation ideally begins three to six months before the target closing. Concretely: set up a structured data room populated with complete financial, legal and commercial documents; build an integrated 3-statement financial model whose assumptions are verifiable; document unit economics consistently over at least six months; and run an internal mini-DD dry run through an investor's lens. Every open question that surfaces in the dry run is a gap that becomes more expensive under real time pressure.
How long does a Series A due diligence take?+
Typically four to eight weeks from data room access. Duration depends on how well the documents are prepared. Companies with a complete data room and clear documentation can shorten the process considerably. Companies that are still gathering documents during DD lose weeks and signal a lack of professionalism.
Which software is suitable for the data room?+
For VC funding rounds, specialised virtual data rooms (VDR) such as Dealroom, Ansarada or iDeals are common. For smaller rounds, a well-structured Google Drive or Notion workspace with granular access control is often enough. What matters is not the tool but the structure: clear folder hierarchy, consistent naming and version control.
What happens if investors find issues during DD?+
It depends on severity. Minor gaps, missing process documentation, incomplete contracts result in follow-up questions and can be supplied later. Serious findings, unresolved tax exposure, IP disputes, misrepresented revenue, can lead to valuation discounts, special conditions in the term sheet, or termination of the process.
What is the most common cause of delays in financial DD?+
Missing or inconsistent numbers. When the financial model does not match the BWA, when unit economics cannot be reconstructed across months, or when the cap table contains contradictions, follow-up questions extend the process by weeks. Financial DD runs fastest when a CFO has built the model and can explain every figure.
Which unit economics do investors expect in financial DD?+
At minimum customer acquisition cost (CAC), lifetime value (LTV), LTV/CAC ratio and payback period. For SaaS companies, additionally monthly recurring revenue (MRR), net revenue retention (NRR) and logo churn. These numbers must not only exist as a snapshot but as a trend over six to twelve months. Investors want to understand whether unit economics are improving or deteriorating.
How does a fractional CFO help with DD preparation?+
A fractional CFO takes overall control of DD preparation: building the financial model, structuring the data room, ensuring KPIs and unit economics are consistently in place, and coordinating input from tax advisor and lawyer. The biggest leverage is the internal mini-DD: the CFO reviews the documents through an investor lens and identifies gaps before they surface in the process. This preparation ideally begins three to six months before the planned fundraising.
How do I build a defensible financial model for DD?+
A DD-ready financial model is an integrated three-statement model (P&L, balance sheet, cash flow) whose planning assumptions are transparent and traceable. Each assumption should either be historically backed or explicitly flagged as a hypothesis. Investors do not only check the numbers but the logic behind them: does the planned growth rate match historical performance? Are personnel costs consistent with the hiring plan? Does cash flow match payment terms?
What IP risks arise from freelancer code without an assignment agreement?+
German copyright law leaves rights with the creator until they are transferred by contract. A services agreement without an explicit IP assignment clause gives the client a usage licence — not ownership of the code. If a freelancer is unreachable three years after the engagement, the gap in the ownership chain is nearly impossible to close retrospectively. In due diligence, this leads either to a condition in the term sheet or a valuation discount. The standard: every freelancer contract needs an assignment clause that transfers all IP rights fully and irrevocably to the company. Where early-stage developers worked without such clauses, the fix is retroactive assignment agreements — assuming the freelancers cooperate. Founders who used many external developers in the early phase without proper IP clauses should address this systematically before DD preparation begins.
Can a founder working abroad trigger a permanent establishment for the company?+
Yes — and the risk is higher for founders than for regular employees, not lower. The OECD commentary update of 19 November 2025 brought clarity for employees: working less than 50 percent of working time from abroad, without a commercial reason for doing so, does not typically create a permanent establishment. Founders and people who are the sole or primary person exercising a company's business are explicitly excluded from these guidelines. The OECD update states that in such constellations the threshold for a permanent establishment is crossed more quickly — without providing detailed guidance. Founders face a second risk on top of this: a CEO who habitually signs contracts and makes strategic decisions from abroad can not only create a permanent establishment but also shift the place of effective management. That triggers corporate tax obligations abroad, double taxation conflicts, and substantial compliance costs across two jurisdictions. Investors check travel patterns, governance protocols and whether decisions are documented as being made in Germany.