Most business owners selling a company for the first time assume that due diligence is something that happens to them — a process controlled by the buyer, designed to find problems and justify a lower price. That assumption is understandable. It is also strategically wrong.
Vendor Due Diligence (VDD) is the practice of commissioning your own independent review of the business before a sale process begins — then sharing that report with prospective buyers. Done well, it is one of the most effective tools available to a seller. It is also, in the UK mid-market, still underused.
What VDD actually is — and isn't
A Vendor Due Diligence report is produced by an independent professional firm — typically an accountancy firm or specialist M&A advisory house — appointed by the seller. The scope mirrors what a buyer's advisers would produce: a financial analysis of the business covering historical earnings, revenue quality, working capital, and normalised EBITDA. Commercial and legal VDD can be commissioned alongside or separately.
The key word is independent. The report is addressed to the seller but written to a standard that buyers and their advisers can rely on. It is not a marketing document. It is not designed to make the business look good. It is designed to give an accurate, professionally verified view of the financial position — which, if the business is well-run, is precisely what benefits the seller.
What VDD is not: it is not a replacement for buyer due diligence. Buyers will still conduct their own review. What changes is the scope, the pace, and the dynamic.
Why sellers commission VDD
1. You find the problems before the buyer does
Every business has complexity. Revenue recognition that could be interpreted differently. A working capital position with seasonal variation. An add-back in the normalised EBITDA that needs careful explanation. A customer that represents 30% of revenue and whose contract is up for renewal in eighteen months.
None of these are necessarily fatal issues. But when a buyer's advisers find them mid-process — without prior context, without the seller's explanation, and with an incentive to use them as negotiating leverage — they become significantly more damaging than they need to be.
A VDD surfaces these issues in advance. The seller can address them, document them properly, or simply have a clear and credible explanation ready. The same issue, presented proactively by a seller in a VDD report with a well-reasoned adjustment, lands very differently than the same issue discovered by a buyer's accountants at week six of a process.
The same issue, presented proactively by the seller in a VDD report, lands very differently than the same issue discovered by a buyer's accountants at week six of a process.
2. You control the financial narrative
A VDD report defines the starting point for financial discussions. It sets the normalised EBITDA. It documents which costs are genuinely non-recurring. It establishes the working capital peg. It presents the revenue analysis on the seller's preferred basis — with the seller's explanation of any anomalies.
Without VDD, the buyer's advisers build their own view of all of these figures. They may reach different conclusions. They will certainly take longer. And their conclusions form the basis of any price chip conversation.
With VDD, the seller's numbers are the starting point. Buyers can challenge them, but they are challenging a professionally prepared, independently verified report — not raw management accounts.
3. You accelerate the process
Transaction timelines kill deals. The longer a process runs, the more opportunity there is for buyer fatigue, management distraction, market changes, or competing priorities to derail it. Every week of delay is a week in which the deal can fall apart.
VDD compresses the timeline significantly. Because the buyer's advisers can rely on the VDD rather than building their own financial analysis from scratch, the parallel due diligence phase is shorter. In competitive processes with multiple bidders, this compression also limits the window in which any individual buyer can use DD as a stalling tactic.
4. You reduce business disruption
Financial due diligence is resource-intensive for the management team. Responding to data room requests, preparing bridging schedules, answering detailed questions on historic accounts — all of this takes time away from running the business at a moment when performance matters most.
A VDD report, produced before the process begins, handles a significant proportion of this work upfront and in a controlled way. The data room is built to support the VDD findings. The financial model aligns with the VDD output. When buyer DD questions arrive, many of them can be answered by pointing to the VDD report — which already exists.
5. In competitive processes, it signals seriousness
A well-prepared VDD tells prospective buyers something about the seller and their advisers: that the process is professionally run, that the seller is confident in the numbers, and that the timeline is real. Buyers who have been through poorly prepared processes — where data rooms are missing documents, management accounts can't be reconciled to statutory accounts, and every due diligence question takes two weeks to answer — notice the difference immediately.
When VDD is typically commissioned: For businesses with revenue above £5M or enterprise values likely to exceed £5M, VDD is worth serious consideration. Below that threshold, the cost may not be proportionate. The strongest cases for VDD are competitive processes with multiple bidders, where controlling the narrative and compressing timelines offer the most value.
What a financial VDD report covers
The scope varies by business, but a standard financial VDD for an SME or growth company will typically address:
- Historical financial performance — three years of P&L, with revenue and margin analysis by product line, customer segment, or geography as appropriate
- Revenue quality — recurring vs one-off, customer concentration, contract terms, renewal rates, and churn analysis for SaaS or subscription businesses
- Normalised EBITDA — documented add-backs with supporting evidence, adjustments for non-arm's-length transactions, and a clear bridge from reported to normalised earnings
- Working capital — analysis of debtor days, creditor terms, stock levels, and a proposed normalised working capital peg for the completion mechanism
- Net debt and liabilities — a complete schedule of all financial liabilities, including HP agreements, deferred income, accruals, and any contingent items
- Capital expenditure — historic capex levels and the distinction between maintenance and growth capex
- Forward-looking context — in some VDDs, the report will include an assessment of the current year trading and the reasonableness of management's forecast
The cost — and the return
Financial VDD costs money. For a straightforward SME, a reputable firm will typically charge £20,000–£40,000. For a more complex business — multi-entity, international operations, deferred revenue — the cost can reach £60,000–£80,000 or more.
Against that cost, consider the alternative. A price chip of 0.5x EBITDA on a £10M deal is £500,000 — a multiple of the VDD cost. A deal that collapses at week eight of due diligence, after the management team has spent three months responding to information requests, costs far more than money.
| Without VDD | With VDD |
|---|---|
| Buyer sets the financial narrative | Seller controls the starting position |
| Issues discovered mid-process become negotiating points | Issues identified and addressed before process starts |
| Buyer DD takes 8–14 weeks | Parallel DD compressed to 4–8 weeks |
| Management team absorbs full DD burden in-process | Majority of DD work done upfront, controlled timeline |
| Price chips more likely, harder to resist | Chips narrower in scope, easier to defend |
The right time to commission VDD
The answer is: earlier than most sellers think.
Ideally, VDD is commissioned six to twelve months before a process launches. This gives time to address any issues the VDD identifies — to clean up the accounts, document the normalisation adjustments properly, or improve the working capital position before the process begins.
Commissioning VDD three weeks before an NDA is signed is better than nothing, but it removes the remediation window. The most value comes from treating the VDD as part of exit preparation, not as a process step.
The most value from VDD comes from treating it as part of exit preparation — not as a step in the process.
Who produces the VDD report
The credibility of the VDD is partly a function of who produced it. Buyers' advisers will assess the quality and reputation of the VDD firm before deciding how much reliance to place on it. The Big Four and top-tier mid-market accountancy firms carry the most weight. Regional firms with a strong M&A track record are also respected.
The VDD firm should be genuinely independent — not the business's existing auditors or accountants, who cannot provide the objectivity that buyers require. Some buyers will also decline to rely on a VDD produced by a firm with a pre-existing relationship to the seller.
The role of the CFO in a VDD process
The VDD firm will need detailed financial information to do their work. Monthly management accounts reconciled to statutory. A documented schedule of normalisation adjustments. Customer-level revenue data. A working capital model. Details of all financial liabilities. This is financial data room preparation — and it is CFO work.
For businesses without an internal CFO, this is one of the strongest cases for fractional CFO engagement in the twelve months before a sale. The fractional CFO prepares the financial data, manages the VDD firm's information requests, and ensures that the output of the VDD accurately reflects the business's financial position.
They then remain on hand throughout the sale process — managing the data room, responding to buyer DD questions, and handling the financial aspects of the transaction from heads of terms through to completion.
A practical checklist before commissioning VDD
- Three years of management accounts reconciled to statutory accounts
- A schedule of all normalisation adjustments with supporting documentation
- Customer-level revenue analysis for the last three years
- A working capital model built from 24 months of data
- A complete schedule of all financial liabilities and commitments
- Cap table with all options, warrants, and outstanding equity instruments
- Current year management accounts to the most recent month
- The financial model with clearly documented assumptions
If any of these are missing or cannot be produced quickly, that is the first thing to fix — before commissioning VDD, and well before a buyer enters the picture.