By DiligensHub team · Last updated
What Is a Data Room Index?
A data room index is the numbered list of every folder and file in the room. Each item gets a number, such as 3.2.1, that everyone can cite.
The index does three jobs. It tells reviewers where to look. It gives every document a short reference for the Q&A log and the disclosure schedule. And a dated copy records what was in the room at each stage.
Numbers read as a path. In 3.2.1, the 3 is the top-level folder and the 2 is a folder inside it. The 1 is the first item there. A reviewer who sees "see 3.2.1" knows where to go without a search.
Without an index, reviewers rely on search and folder names alone. That works for a small room, but not for thousands of files.
What Folder Structure Should a Data Room Use?
Mirror the due diligence checklist, with one top-level folder for each area. Keep to three levels where you can: area, topic, then documents.
Here is a sample index for a company sale. Its top-level folders follow our M&A due diligence checklist, with litigation given its own folder.
| Index | Folder |
|---|---|
| 1 | Corporate |
| 1.1 | Constitutional documents |
| 1.2 | Group structure and capitalization |
| 1.3 | Board and shareholder minutes |
| 2 | Financial |
| 2.1 | Audited financial statements |
| 2.2 | Management accounts |
| 2.3 | Budget and forecast |
| 3 | Tax |
| 3.1 | Corporate income tax returns |
| 3.2 | Sales and indirect tax returns |
| 4 | Commercial contracts |
| 4.1 | Customers |
| 4.2 | Suppliers |
| 4.3 | Partners and distributors |
| 5 | Employees |
| 6 | Intellectual property |
| 7 | IT and data protection |
| 8 | Real estate |
| 9 | Environmental |
| 10 | Insurance |
| 11 | Regulatory |
| 12 | Litigation |
A few rules keep the structure usable:
- Keep the top-level order the same on every deal, so your team always knows where tax lives.
- Make one folder per topic, not one per bidder. Control who sees what with permissions instead.
- Keep drafts and internal notes out of the room entirely.
- Put a document in one place only. Refer to it from elsewhere by its number.
How Should You Name Files in a Data Room?
Name each file so a reviewer knows what it is without opening it. Use one pattern throughout: what it is, who it's with, and the date.
| Instead of | Use |
|---|---|
| scan_0042.pdf | Supply agreement - Customer A - 2024-03-01.pdf |
| Minutes FINAL v3.docx | Board minutes - 2025-06-12.pdf |
| Lease.pdf | Lease - Head office - 2023-01-15.pdf |
| TB.xlsx | Trial balance - 2025-12-31.xlsx |
- Write dates as year, month, day (2025-06-12), so files sort in date order.
- Leave "final" and "v2" out of names. Upload a new version of the same file instead.
- Upload signed copies, not drafts, unless the draft is the point.
- Put one document in each file, so each one gets its own number.
- Convert to PDF where you can. Keep spreadsheets in their own format when buyers need the formulas.
When Should You Renumber a Data Room Index?
Renumber once, before buyers arrive, and as little as possible after. Once people cite numbers in Q&A and notes, a change breaks every reference.
Numbers drift for two reasons. Folders get moved, or items are deleted and leave gaps. Gaps can also leak information. If a bidder sees 4.1 and 4.3 but not 4.2, it knows a folder is hidden from it.
- 1.Finish the structure before the first invitation goes out.
- 2.Renumber once, at the end of preparation, to close any gaps.
- 3.After launch, add new items at the end of their folder, not in the middle.
- 4.If you must renumber later, tell every party and send them the new index.
How Does the Index Change by Deal Type?
The core areas stay the same, but each deal type adds its own folders. Put the additions where reviewers expect them, near the areas they relate to.
| Deal type | What to add |
|---|---|
| Sell-side M&A | A folder for the confidential information memorandum and management presentation, and one for Q&A attachments |
| Buy-side due diligence | Folders for your advisors' reports, kept apart from the target's documents |
| Capital raise | The pitch deck, cap table, and prior funding round documents, near the top |
| Debt financing | Existing facility agreements, security documents and covenant reporting |
| Real estate | A folder per property, each with title, leases, surveys and permits |
Keep these additions in your template once they work. The next deal of the same type then starts from a tested structure.
What Are Common Data Room Index Mistakes?
Most index problems come from building the room in a hurry, or changing it after buyers arrive. Each one is easy to avoid with a plan.
- No plan before upload. Files go in as they arrive, and the structure grows around them. Plan the folders first.
- One folder per bidder. The same contract ends up in five places, with five numbers. Use permissions instead.
- Late renumbering. Every reference in Q&A and every reviewer's notes stops matching.
- Vague names. Reviewers open files just to find out what they are.
- Duplicates. Two copies of one contract, with different dates, raise questions about which is current.
- Empty folders. A folder with nothing in it invites a question. Add a short note, or remove it until it has content.
Questions
- What is a data room index template?
- A template is a ready-made folder list you adapt to each deal. Our due diligence checklist works as one. Each area becomes a top-level folder, and each request becomes a folder or file inside it.
- How many folder levels should a data room have?
- Aim for three: area, topic, then documents. Deeper trees make files harder to find. They also produce long numbers, like 4.2.1.3.2, that people misread and mistype.
- Should the index match the purchase agreement?
- It helps when it does. Lawyers refer to documents in the disclosure schedule, and index numbers make those references exact. Agree the final index with both sides' lawyers before signing.