Due Diligence Checklist: An M&A Expert List of All the Documents You Need

A complete M&A due diligence checklist contains 98 documents across 9 workstreams: legal (8), financial (19), sales and marketing (10), human resources (10), property/plant/equipment (4), contracts (11), intellectual property (15), corporate good-standing (11), and real estate (10). Most M&A deals run a 60-90 day diligence period, with sellers typically delivering the initial document set within 30 days of LOI signing.

We applied our team's deep M&A expertise into developing this comprehensive checklist along with the free tools and visualizations in this post.

First and most valuably, you can download our free comprehensive checklist here:

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Beyond the asset itself, here is more background on what's covered in the checklist along with some additional custom tools we built for those conducting due diligence.

First you can use the interactive checklist tool below to track your progress against the key documents:

We also built this due diligence timeline planner to help answer one of the most common due diligence questions: how long will the due diligence process take?

Complete Due Diligence Template - All 98 Documents in 89 Workstreams

Having a solid due diligence checklist is essential to keep track of your due diligence progress. Here's a list of the core due diligence documents:

1. Legal Due Diligence Checklist (8 Documents)

A comprehensive legal due diligence checklist requires 8 documents, including shareholder certificates, business licenses and permits, and the company's outstanding legal cases. These documents establish whether the target has clean ownership, regulatory standing to operate, and no undisclosed litigation exposure for the buyer.

These documents generally cover all legal aspects of a company’s operations. These are some of the most important documents a buyer would ask during this process, which are essential for the seller’s business. Here are the key types of legal, due diligence documents:

• Shareholder certificate documents
• Local/state/federal business licenses
• Occupational license
• Building permits documents
• Zonal and land use permits
• Tax registration documents
• Power of attorney documents
• Previous or outstanding legal cases

Don't miss our complete legal due diligence checklist.

2. Financial Due Diligence Checklist (19 Documents)

A comprehensive financial due diligence checklist requires 19 documents, including 3+ years of audited financial statements, all loan and credit agreements, and the company's full capital structure. These documents establish the target's true earnings power, debt obligations, and balance-sheet risk for the buyer.

Financial due diligence documents are essential in assessing the financial health and viability of a company. These documents provide a clear view of the target company's financial status and performance history. Here are some of the most important financial documents commonly requested during M&A:

• Up-to-date tax return documents
• Audited financial statements (at least 3 years)
• Auditor's correspondence for the last five years
• Copies of all loans and credit agreements
• Details of company investments (bonds, marketable securities, etc.)
• Capital structure
• Projections, capital budgets, and strategic plans
• Up-to-date tax and pension liabilities
• Details on when contracts and leases are renewed and whether the terms change
• Details of stockholders (percentage holdings, voting rights, etc.)
• Foreign exchange reserves
• List of unrecorded liabilities
• List of collateral for debt
• Details of owner withdrawals (if any)
• Revenue by client (if possible)
• Gross margins analysis
• Fixed/variable expenses analysis
• List of non-operational expenses
• General ledger

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3. Sales and Marketing Due Diligence Checklist (10 Documents)

A comprehensive sales and marketing due diligence checklist requires 10 documents, including the sales and marketing strategy overview, revenue by customer, and details of existing sales contracts with their expiration dates. These documents establish the durability of revenue and the customer-concentration risk for the buyer.

• Detailed overview of sales and marketing strategy
• Marketing/sales coordination protocols
• Revenue listed by customer
• Exhibit the relationship between marketing expense and revenue growth
• Details of existing sales contracts (and when they expire)
• List of top 10 suppliers
• Sales reports by category of product or service
• Details of credit terms with customers
• Current market share (if possible)
• Percentage of sales from each channel (e.g., online, offline, direct sales, etc.)

4. Human Resources Due Diligence Checklist (10 Documents)

A comprehensive HR due diligence checklist requires 10 documents, including the full employee and contractor roster, employment terms and contracts, and worker's compensation and unemployment claims history. These documents establish the workforce cost structure, key-person risk, and inherited employee liabilities for the buyer.

• Provide a list of current employees and independent contractors
• Employee Rules of Conduct Handbook and Safety Policies
• Detail past employee disputes (if any)
• Detail employee and independent contractor terms of employment
• Detail updated employee resumes
• Outline the policy of working with labor unions (if any)
• Outline training conducted with existing employees
• Worker's compensation/unemployment claims history
• Outline policy of bonuses, incentives, commissions, and deferred commissions
• Detail policies for sick days, paid holidays, paid vacations, and overtime pay

5. Property, Plant, and Equipment Due Diligence Checkist (4 Documents )

A comprehensive property, plant, and equipment due diligence checklist requires 4 documents covering equipment, real estate, technology, and inventory. These documents establish the target's tangible asset base - what the buyer is actually acquiring on the balance sheet beyond the operating business.

• Equipment
• Real estate
• Technology
• Inventory

6. Contract Due Diligence Checklist (11 Documents)

A comprehensive contract due diligence checklist requires 11 documents, including all customer contracts, supplier and joint-venture agreements, and equipment leases plus loan and credit guarantees. These documents establish the change-of-control consents the buyer will need at closing and the contractual obligations being assumed.

• Customer contracts
• Supplier contracts
• Joint venture/partnership agreements
• Settlement agreements
• Franchising agreements
• Accounts receivable schedule
• Accounts payable schedule
• Equipment leases
• Non-compete agreements
• Employee contacts
• Loans, credits, and guarantees agreements

7. Intellectual Property Due Diligence Checklist (15 Documents)

A comprehensive intellectual property due diligence checklistrequires 15 documents, including issued patents and patent applications, trademarks, and all licensing agreements (both inbound and outbound). These documents establish the target's IP ownership, freedom to operate, and the licensing-revenue obligations being acquired by the buyer.

• Trade secrets
• IP claims and litigation
• Domain names
• Issued patents
• Patent applications
• Design patents
• Design patent applications
• Industrial designs
• Industrial design applications
• Liens on intellectual property
• Copyrights
• Licenses
• Licensing agreements
• Trademarks
• Agreements/documents regarding ownership and rights of use of advertising copy, trademarks, logos, and slogans

8. Company's Good Standing and Organization Due Diligence Checklist (11 Documents )

A comprehensive corporate good-standing and organization due diligence checklist requires 11 documents, including the organizational chart, articles of incorporation and bylaws, and a Certificate of Good Standing from each Secretary of State where the company conducts business. These documents establish that the target is a legitimately organized entity with the corporate authority to enter into the transaction.

• Organizational Chart
• Shareholders/percentages owned
• Voting trusts, subscriptions, calls, puts, options, and convertible securities agreements
• State of incorporation status reports for the last three years
• Assumed names
• Company minutes book
• Company bylaws and amendments
• List of the states and countries where the company has employees owns assets, leases assets, and does business
• The Articles of Incorporation/amendments.
• Annual reports for the last three years.
• A Certificate of Good Standing from each Secretary of State where the company conducts business

9. Real Estate Due Diligence Checklist (10 Documents)

A comprehensive real estate due diligence checklist requires 10 documents on top of the standard 88-item checklist, including a title insurance commitment, an ALTA/NSPS land title survey, and a Phase I environmental site assessment. These documents establish that the property has clean title, defined boundaries, and no environmental liabilities the buyer would inherit.

If the target company owns or operates real estate, an additional 10 documents sit on top of the standard 98-item checklist. These are typically pulled in by either the buyer's real estate counsel or a third-party title company, and the deadline to deliver them is usually written into the purchase agreement as a "real estate due diligence period" of 30-60 days.

• Title insurance commitment - issued by the title company, lists encumbrances, easements, and required endorsements.
• ALTA/NSPS land title survey - the current-standard boundary survey required by most institutional lenders.
• Phase I environmental site assessment (ESA) - per ASTM E1527 standard; required for Innocent Landowner Defense under CERCLA.
• Phase II ESA (if Phase I flags recognized environmental conditions) - subsurface soil and groundwater testing.
• Zoning verification letter - municipal confirmation of allowed uses, setbacks, and any nonconforming-use status.
• Certificate of occupancy - current CofO for each building/unit.
• Rent roll and lease abstracts - current rent roll plus abstracts for all leases over 5,000 sq ft or 5% of NRA.
• Operating expense recoveries (CAM) reconciliations - last 3 years, to validate the underwriting NOI.
• Property condition report (PCR) - structural, mechanical, roof, and parking-lot assessment with deferred-maintenance estimate.
• Real-estate tax bills and assessment appeals - last 3 years of bills plus any pending or recent appeals.

For deals where real estate is the primary asset (rather than incidental to an operating business), the buyer's diligence team typically also pulls a separate set of documents covering the surrounding submarket - tenant financial statements, comparable lease and sale data, and traffic counts - which fall outside this checklist's scope.

When Should You Provide Due Diligence Documents to the Buyer?

Keeping thorough and updated due diligence documents allows you to get relevant information over to the buyer of your business efficiently and with as little friction as possible. But the question then arises:

• When should due diligence documents be provided to the buyer?
• Can this be done too quickly?

Absolutely. Unfortunately, the world of M&A is full of tire-kickers who enjoy finding out about businesses simply to see what’s out there. Asking you for due diligence documents rarely costs them anything (hence the reason why some bankers push for charging buyers for due diligence).

The best policy is to begin by providing audited financial statements - a great signaling device for any owner looking to sell their business that their ship is in order - and send over documents as they’re requested by the buyer, who should have signed an NDA in advance.

The more buyers you speak to, the more likely you’ll be able to anticipate what documents they’re looking for in advance, making the process even more efficient.

How to Collect and Share Due Diligence Documents

What emerges from all the documents outlined above is a true understanding of the business for sale and what’s ‘under the hood.’

Many of the documents will be partially or fully available straight away (for example, details of your employees and their training to date), while others, such as the audited financial statements, will, by their very nature, take longer to put together.

Below, we will share and compare how to collect and share due diligence documents using the old-school way, and the modern approach of doing M&A. 

The Old School Way: Using Excel Sheets

Collecting due diligence documents should be done in a systematic manner that allows you to see where documents can be obtained, whether more should be added, progress reports on their collection and more. We suggest putting together a list in a table format structured similarly to the one provided below:

Keeping structured records like this in a spreadsheet also allows you to filter for results faster. Whatever headings you opt for, the ‘last updated’ column is particularly important, allowing you to see at a glance when due diligence documents were last updated and, thus, how likely they are to be relevant.

However, using spreadsheets has limitations, risks, and inefficiencies. 

1. Data security - Excel doesn't have robust security features. Sensitive information could be at risk, especially if you send it via email to various stakeholders. 

2. Time-consuming - Using Excel involves relying on manual data entry, which can be extremely time-consuming. Also, with the number of people involved in an M&A deal and different people from different departments touching the spreadsheet, errors will likely occur. One wrong formula, formatting, or data entry can wreak havoc on the entire spreadsheet.

3. Real-time collaboration-  Excel Sheets are not designed for real-time collaboration, which can cause bottlenecks and inefficiencies. Team members will have to wait for the latest version of the file before they can start working on their part. If not, they could be working with outdated information or duplicating someone else’s work. 

4. Integrated communication: Communication in Excel trackers relies on external channels, such as email or messaging apps. This can lead to fragmented discussions and a lack of context within the platform, creating confusion.

5. Cannot store diligence files - Excel cannot store files and will also rely on third-party applications. This limitation often results in confusion, lost files, or hard-to-find files. 

A Better Way to do M&A: DealRoom M&A Optimization Platform

DealRoom on the other hand, is an M&A Optimization platform purpose-built by M&A practitioners. It’s designed to handle the entire M&A process, from pipeline management and due diligence to integration. Let’s take a look at some of the advantages of using DealRoom.

1. Save 20+ hours/deal - DealRoom is a unified, end-to-end M&A platform that allows users to centralize all deal data and communication. This enables M&A teams, both internal and external, to save significant time and, therefore, money. In addition, DealRoom users can automate playbook creation to remove duplicative and time-consuming playbook creation tasks for every single deal.
2. Reduce cost - Because DealRoom M&A Platform is an all-in-one platform, instead of relying on and paying for a broad set of tools, teams can reduce their technology expenses. The increased efficiency that DealRoom powers also reduces billable hours and accelerates deal velocity, contributing to lower costs. 
3. Increases Alignment - What truly sets DealRoom apart from other software is its parallel workstream capabilities. It allows the diligence team and the integration team to work together simultaneously, more specifically, it empowers the integration teams' earlier visibility of deal theses.  Which, in turn, increases the success rate of deal value capture.  

While Excel Sheets have served well in the past, there are new and better ways to do M&A in this modern era. For more information about how to use DealRoom for this process, check out DealRoom for due diligence.

Frequently Asked Questions

What is due diligence in the context of startups and investments?
Due diligence is the research investors do before funding a company. It involves reviewing the business, financial records, and potential risks. The goal is to confirm the company’s claims and understand whether the investment fits the investor’s goals.

Why are due diligence documents important?
These materials build trust and transparency. They help investors confirm the company’s financial condition, legal status, and growth outlook before committing funds.

What are the main categories of due diligence documents?
Here is a quick overview:

• Corporate documents: formation papers, ownership records
• Financial documents: balance sheets, income statements, forecasts
• Legal documents: contracts, patents, compliance filings
• Operational documents: business plans, key metrics, customer data
• Market analysis: competitors and industry trends

Who prepares due diligence documents?
Founders and management teams gather the materials. They often work with attorneys and accountants to ensure accuracy. During review, investors may ask for more details or updated files.

How does Dealroom help with due diligence?
Dealroom offers verified company data and analytics that make the review faster. Investors use the platform to check facts, benchmark performance, and find similar companies for comparison.

What is a data room, and how is it used in due diligence?
A data room is a secure online folder where companies upload due diligence materials. It gives investors controlled access and keeps sensitive information private.

How long does the due diligence process usually take?
It depends on the deal size and company complexity. Early-stage startups may close in weeks, while larger firms or regulated industries might take months.

What are common red flags investors look for during due diligence?
Investors watch for gaps or inconsistencies in records. Warning signs include mismatched financial data, pending legal cases, vague ownership, customer churn, or inflated forecasts.

How can startups prepare for due diligence in advance?
Keep records current, follow financial and legal rules, and organize files in a central location. Tools like Dealroom help startups show verified data to investors with confidence.

What is the due diligence documents delivery deadline?
The delivery deadline is the date by which the seller must hand over all due diligence documents to the buyer, set in the purchase agreement (or, in real estate, the purchase and sale agreement). Most M&A deals set a 30-day initial delivery deadline after the LOI is signed, with a separate 60-90 day "diligence period" during which the buyer can request follow-up materials. If the seller misses the delivery deadline, the buyer typically gains the right to extend the diligence period or terminate the deal without penalty.

What is the due diligence documents objection deadline?
The objection deadline is the date by which the buyer must raise issues with the documents received - missing items, inaccuracies, or red flags that materially affect valuation. After this date, the buyer typically loses the contractual right to walk away over those specific issues, though warranties and indemnities in the final purchase agreement may still preserve some recourse. The objection deadline is usually set 5-10 business days before the diligence period ends, giving both sides time to negotiate fixes or price adjustments before the closing window.

How long does it take to collect all 88 due diligence documents?
For a mid-market M&A deal, sellers typically take 2-4 weeks to assemble the initial 88-document package - faster if the company has been organized in a virtual data room throughout the year, slower if documents are scattered across folders, email, and various department leads. Documents that are immediately available (employee lists, tax registrations, bylaws) can be delivered within days; audited financials and IP filings often take the longest because they require coordination with external auditors and counsel. The full diligence period - from initial delivery through buyer review, follow-up requests, and objection deadline - typically runs 60-90 days for a strategic acquisition and 30-45 days for a financial-sponsor deal.

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