What to Put in an M&A Data Room (UK Checklist, 2026)

An M&A data room checklist tells you which documents a buyer will expect to see when they carry out due diligence on your company, and how to organise them so the deal moves quickly rather than stalling. In broad terms, an acquisition data room needs to cover the corporate structure, the finances, the material contracts, the legal and intellectual property position, the people, and any regulatory or compliance matters. A well-populated, well-structured room signals a well-run business and speeds up the process; a thin or chaotic one invites questions, price chips and delay. This guide sets out what to include, section by section, and how to share it all securely. It is general information, not legal advice.

Whether you are a founder selling a startup or an owner exiting a mature business, the data room is where the buyer's advisers form their view of what they are buying. Preparing it properly before you go to market is one of the highest-return things you can do, because gaps and inconsistencies found late are far more damaging than the same issues disclosed cleanly up front. If you are new to the concept, our explainer on what a virtual data room is covers the basics, and our guide on how to set up a data room in under an hour walks through the mechanics.

Corporate and constitutional documents

Buyers start with the legal foundations of the company, because everything else sits on top of them. This section establishes that the business exists as claimed, that its ownership is what the seller says, and that decisions have been made properly.

Include the certificate of incorporation and any certificates on change of name, the current articles of association, and any shareholders' agreement. Provide an up-to-date cap table and the statutory registers, including the register of members and the register of people with significant control. Add the board minutes and resolutions for material decisions, and any shareholder resolutions, so the buyer can trace how key steps such as share allotments were authorised. This is where the corporate governance trail we cover in our guide on sharing board papers securely with directors becomes part of the deal, and where a clean, consistent cap table reassures the buyer that ownership is exactly as described.

Financial information

The financial section is scrutinised harder than any other, and it is where a buyer's advisers will spend most of their time. Consistency across documents matters as much as the numbers themselves.

Include statutory accounts for the last three years, recent management accounts, and current-year financial statements. Provide the financial model or forecast, along with the key assumptions behind it, so the buyer can test the projections. Add details of debt and financing arrangements, bank facilities, any charges registered against the company, and the tax position, including recent returns and any correspondence with HMRC. A schedule of aged debtors and creditors, and details of any grants or R&D tax relief claimed, round the section out. Presenting all of this cleanly is important, and our guide on sharing a financial model without losing control explains how to do it without handing over an editable spreadsheet that circulates freely.

Commercial contracts, legal and IP

This section shows the buyer what the business is actually committed to and what it owns. It is often the largest part of the room and the one where a structured request list keeps things manageable.

On the commercial side, include material customer and supplier contracts, standard terms of business, partnership and distribution agreements, and any leases or property documents. On the legal side, cover intellectual property (registered trademarks and patents, and the assignments proving the company owns its IP), licences, data protection and privacy documentation, and details of any current or threatened litigation. Insurance policies belong here too. Because buyers often work from a structured list of requests, our due diligence request list template mirrors the way advisers ask for these documents, which makes it easier to respond in the order they expect.

People and regulatory

Employees, contractors and compliance make up the final substantive section. Buyers want to understand the workforce they are acquiring and any liabilities attached to it.

Include an anonymised employee list with roles, start dates, salaries and notice periods, template and material employment contracts, consultancy agreements, and details of any share option scheme and its rules. Cover pension arrangements, and any employment disputes or grievances. On the regulatory side, include any licences or permissions the business needs to operate, health and safety documentation where relevant, and evidence of compliance with sector-specific rules. For smaller transactions, our guide to the best data room for M&A under thirty million pounds covers how to keep this proportionate rather than drowning a modest deal in paperwork.

How to organise and share it all securely

Having the right documents is only half the job; a buyer's experience of your room shapes their confidence in the deal. Organise the room to mirror the sections above, keep the hierarchy shallow and clearly numbered, and upload final versions with clean, readable file names. A structured room, aligned with the buyer's own checklist, lets their advisers work through it without constant back-and-forth. Our fundraising data room checklist and our roundup of the best data room for due diligence in the UK are useful companions when you are deciding how deep to go.

Security matters as much as structure, because you are handing your most sensitive documents to a party who might, in the end, not buy. You want to control who sees what, know who has looked at what, and be able to withdraw access if the deal falls through. That means gating access, sharing tracked links rather than attachments, watermarking the most sensitive files, and keeping the power to revoke.

How 99 Data Rooms handles M&A due diligence

99 Data Rooms is built for exactly this: sharing a large, sensitive document set with a counterparty while keeping full control of it.

You create a virtual data room structured to match your checklist, upload the documents, and share access as tracked, revocable links. Gating requires a verified email and a one-time code before anyone opens the room, and on the Business tier you can require an NDA first and watermark documents with the viewer's identity, which deters leaks of the most sensitive files. Page-by-page analytics show you which sections the buyer's advisers are working through and how long they spend, a genuinely useful signal of where the deal's attention sits. If a document does not exist yet, the live AI Legal Drafting feature assembles it from vetted England and Wales clauses. When the deal completes, e-signature in the browser returns audit-certified PDFs, and if a bidder drops out, one click revokes their access across the whole room. Structured, gated, tracked, watermarked and revocable: your due diligence set stays under your control from first bidder to completion.

Build your M&A data room for free

You can build a structured, gated, tracked M&A data room and share it with bidders while keeping full control, all inside 99 Data Rooms. The free tier is a real tier, not a trial: three rooms, twenty-five active links, forever, no card required. Start for free, structure your room around the checklist above, and move up only when you want unlimited links, NDA gating or watermarking. The wider platform is in beta and improving fast, but the due diligence loop from structured room to tracked, revocable access already works today.

Sources

• Records of directors' meetings (corporate documents referenced): Companies Act 2006, s.248, https://www.legislation.gov.uk/ukpga/2006/46/section/248