Legal Due Diligence: Process, Cost, Timeline and Checklist

In BRG's 2026 M&A Disputes Report, 81% of more than 200 deal lawyers, private equity professionals and advisors said the number of M&A disputes they worked on rose in 2025. Legal due diligence is the buyer's review of a target company's corporate records, contracts, litigation, intellectual property, licenses and employment matters before signing, so liabilities are found and priced before closing rather than disputed after it.

After more than a decade as an M&A advisor running a boutique practice, this is the legal due diligence process, timeline, cost and checklist I use, plus where the findings land in the purchase agreement.

How much does legal due diligence cost?

Legal due diligence is billed mostly by the hour, so the budget depends on the team's rates and on how organized the seller's data room is. Clio's 2025 Legal Trends data puts the average US lawyer rate at $349 per hour and non-lawyer staff at $187, and rates are rising: LexisNexis Counsel Link's 2026 Trends Report found M&A partner rates up 8.8% in 2025, and Thomson Reuters recorded a record 7.3% rise in worked rates across US law firms the same year. At the top of the market a few partners now bill $3,000 to $4,000 per hour (ABA Journal, January 2026). It is still cheaper than finding legal problems six months after closing.

Don’t cut corners or you may end up paying far more than you expected down the line. Instead, create a clear agenda with the law firm and legal experts you hire, establishing where and when the costs will arrive so everyone knows what to expect.

How to perform legal due diligence

During LDD, the legal teams on both the buy side and the sell side will conduct due diligence investigations into the target company’s legal background, operations, and documentation. The goal is to uncover potential risks, review regulatory compliance, and understand current liabilities. 

The LDD process will likely begin with a general review of the target company’s legal standing, and then move into an in-depth examination of the following areas:

• Organization/ownership
• Litigation
• Product/service
• Contracts/obligations
• Permits/licenses
• Intellectual property
• Material assets
• HR/operations

Legal due diligence on the sell-side

It’s good practice for owners on the sell side to conduct at least part of the legal due diligence process. For one, having an external attorney sign off on some of the internal legal workings of your company is a courteous way to treat buyers. For another, it speeds up the process and better prepares your business for a frictionless and timely sale. If both companies have in-house legal teams, sell-side LDD is also their first working contact, which pays off once integration planning starts.

Legal due diligence on the buy side

The main goal of LDD on the buy side is to ensure the target company doesn’t have any hidden legal problems that could make the sale fall through. However, LDD also helps ensure a fair valuation and purchase price and can inform the details of the purchase agreement. 

How long does legal due diligence take? 

Legal due diligence runs inside the overall diligence window. In our due diligence process guide we put a standard timeline at about six weeks (30 to 45 business days) from LOI to the closing decision, with 3 to 4weeks possible on clean, well-documented targets and 10 to 12 weeks or more on cross-border or regulated deals. The legal workstream usually tracks the long end of that range because consents, regulatory filings and historic contracts take time to retrieve.

Although LDD can be time-consuming, it’s well worth it to be as thorough as possible. 

How to ensure a smooth LDD process

The most efficient way to conduct legal due diligence is via a virtual data room, which will be shared between the buy side, the sell side, and the legal teams on both. The buy side, in tandem with their attorney, should agree to a checklist of legal documents that will be requested from the sell side.

It’s important to establish some order at the outset. Begin processes that inevitably take longer first. Your attorney will know from experience which documents take the longest, but a good rule of thumb is: The further back you go with a document that can’t be retrieved in-house, the lengthier the process will be. 

What goes into a legal due diligence report

The legal due diligence report is the deliverable the whole review builds toward: a written summary of what counsel found, ranked by severity, with a recommended action for each issue. Formats range from a short red flag memo on a small deal to a full annotated report on a regulated one; agree the format with counsel before the requests go out. A useful report has five parts.‍

Executive summary: the deal breakers, the issues that change price or structure and the items that need a fix before closing, in one or two pages.‍

Scope and limitations: which documents were reviewed, which were missing from the data room and which areas were excluded.‍

Findings by area: corporate and ownership, contracts and change of control, litigation and investigations, intellectual property, employment, permits and regulatory, each with the documents reviewed and the exposure found.‍

Recommended actions: for every material finding, the proposed remedy, which is usually a price adjustment, a specific indemnity, an escrow, a closing condition or a required consent.‍

Open items: requests still outstanding and the date they are needed by.

Therecommendations matter because they are negotiated into the purchase agreement.In SRS Acquiom's 2026 M&A Deal Terms Study of more than 2,300private-target deals, as summarized by Fasken, representations andwarranties insurance appeared on about 46% of deals, earnouts on 24% of 2025deals and the median indemnification escrow was 10% of deal value on dealswithout RWI against 0.5% with it. Those are the levers a report should pointto. BRG's 2026 M&A Disputes Report found thatearnouts and representations and warranties featured most often in 2025disputes, which is where a thin report shows up later.

In our State of AI in M&A 2026 report, 26% of 237 practitioners named due diligence as the area where AI will have the greatest impact over the next 12to 24 months, and first-pass contract review and report drafting are where that lands first. Date and version the report and keep it in the data room next to the request list so the integration team can pick up the open items after closing.

The importance of obtaining a legal opinion on the target firm

Even if your LDD process doesn’t raise any red flags, M&A always comes with some element of legal risk.

This is where legal due diligence differs from other parts of the process. Many of the risks you’re trying to uncover here won’t be hiding in plain sight. Suppose you’re acquiring a small pharmaceutical firm that sells drugs with some potential side effects that haven’t caused any issues until now. What are these side effects and what kind of liability would they create for your company should one (or several) of your customers be hit with them?

Answering questions like these is where your legal team pays for itself. Their findings arrive as a legal due diligence report with a recommendation on each issue: proceed, reprice, adda specific indemnity or escrow or walk away. That is different from the formal legal opinion letters counsel deliver at closing, which cover narrower points such as the target's corporate authority and the enforceability of the transaction documents. The answer will rarely be a straight “yes” or “no,” but at least you’ll be making a far more informed decision based on their legal advice.

A legal due diligence checklist for M&A 

The LDD process has a lot of moving parts. Having a checklist in place helps keep everyone organized and on-task from beginning to end. Below, we’ve laid out a basic checklist by LDD category that you can fit to your own needs.

General

• Obtain copies of agreements or instruments that place restrictions or encumbrances on assets.
• Review contracts that restrict the target's right to conduct its business.
• Review contracts with obligations such as covenants and indemnification.
• Obtain a summary of the target's compliance program and copies of all policies, procedures, and other related documentation.
• Confirm that the firm is not restricted from doing business under OFAC regulations or similar.
• Confirm whether the target has any direct or indirect presence and/or other engagements.
• Obtain a summary of regulations applicable to the business, and anticipated changes.
• Create copies of any letters with any regulatory agencies or authorities.
• List the states and countries in which the target has operations.
• Obtain good-standing certificates or qualifications to do business from state of incorporation and states where qualified.
• Obtain a schedule of any significant U.S. import or export restrictions that relate to the target's operations.

Organization/Ownership

Obtain lists of:

• Current shareholders detailing the amount of shares each owns
• Stock transfer records
• Stock broker contracts and agreements
• Gather evidence that outstanding stock is paid in full.
• Identify issues associated with transferring equity.

Litigation

• Obtain lists of: 
  • All threatened, pending, current, and closed litigations from the past five years
  • Arbitration proceedings from thepast five years
  • All statutory orders, decrees, and rulings to which the company may be subject
• Gather summaries of current and closed governmental investigations and proceedings on the target, directors, and executives from the past five years.
• Obtain responses from the company regarding audit inquiries.

Product/Service

• Obtain a detailed list of all products and services.
• Verify compliance with FDA, CPSC, OSHA, and FLSA regulations for products, services, and operations.
• Get copies of all product warranties.
• Summarize all submitted material warranty claims.
• Summarize all product recalls.
• Identify potential liabilities associated with products/services.

Contracts/Obligations

• Obtain copies of:
  • Service contracts
  • Vendor contracts
  • Customer contracts and obligations
  • Outstanding contracts to purchase machinery or real estate
  • Contracts for construction, architectural, or engineering services for any buildings or improvements
  • Operating contracts
  • Employee contracts and retirement agreements
  • Non-compete, non-solicit andexclusivity agreements
  • Material contracts that are terminable upon a change of control or other corporate transaction
  • All joint venture, partnership, and franchise agreements
• Identify any contracts or provisions that may be out of the ordinary course of business.

Permits/Licenses

• Summarize permits, licenses, and other authorizations, including any required export control and pertinent governmental licenses.
• Summarize license, sublicense, royalty, and franchise agreements.
• Obtain a schedule of permit and license renewals and associated fees.
• Gather copies of automobile registrations.

Intellectual Property

• Obtain lists of all:
  • Patents, trademarks, trade names, service marks, and copyrights held or applied for
  • Creator(s) for each IP component
  • Patents, trademarks, and copyrights held by an employee, shareholder, director, or any other affiliated party
• Summarize material trade secrets.

Material Assets

• Obtain lists of equipment and real estate.
• Summarize inventory stock.
• Summarize all technology owned by the company. 

HR/Operations

• Obtain a list of all employees, including those covered by disability legislation.
• Obtain a list of OSHA citations, employee health issues related to the target, and any other adverse environmental or occupational safety or health conditions or concerns.
• Get a history of all sexual harassment accusations, charges, and convictions from the past five years.
• Obtain copies of all current employment applications, interview guides, and hiring procedures.
• Verify compliance with equal employment opportunity and anti-discrimination legislation.
• Summarize disciplinary and termination procedures and all involuntary employee terminations from the past five years.
• Review all Unemployment and Workers’ Compensation claims.
• Verify compliance with the Fair Labor Standards Act, i.e. minimum wage, child labor, etc. (if U.S.-based).
• Ensure employee personnel files and Form I-9s are in compliance with legal standards.
• Obtain copies of all Summaries ofBenefits and Coverage (SBCs) for current benefit plans.
• Obtain copies of all union and labor contracts.
• Review any labor-related disputes, grievance proceedings, and arbitrations.
  

Get your complete legal due diligence checklist here.

Legal due diligence in a foreign country

The importance of conducting legal due diligence when acquiring a foreign firm, entering a joint venture, or beginning a business partnership cannot be overstated. This is as true for foreign companies coming to the United States as it is for American companies moving abroad: Different legal environments bring new risks: sanctions and export controls, anti-corruption laws such as the FCPA and the UK Bribery Act, local employment rules and foreign investment screening. Inbound US deals may need a filing with CFIUS, the Treasury-chaired committee that reviews certain foreign investments in US businesses for national security effects, and many other jurisdictions now run equivalent regimes.

Accordingly, they require proper assessment. When looking into acquiring a company in a foreign jurisdiction, shop around among the local legal firms to determine which ones best fit your requirements in terms of service and cost. Once the transaction is closed, the relationship with this legal team may become long-term, so it’s worth putting extra time in at the outset to ensure it works for your firm.

Frequently asked questions

What is included in legal due diligence?

Legal duediligence covers nine areas: corporate organization and ownership, litigation,products and services, contracts and obligations, permits and licenses,intellectual property, material assets, HR and employment and generalregulatory compliance including sanctions checks under OFAC. In practice thebuyer's counsel issues a document request list under each heading, the selleruploads the records to a virtual data room, and the lawyers review them forliabilities, consents and change of control triggers. The checklist on thispage lists the specific documents to request under each of the nine areas.

Who conducts legal due diligence?

Legal duediligence is conducted by the buyer's lawyers. Outside M&A counsel leadsthe review, the buyer's in-house legal team sets the scope and specialists intax, employment, intellectual property, privacy and regulatory law cover theirown areas. The seller's counsel responds to the document requests, and onlarger sales the seller may commission a vendor due diligence report beforegoing to market. On small deals a single corporate lawyer may conduct the wholelegal review; on cross-border deals, local counsel in each jurisdiction isadded.

What is a legal due diligence report?

A legal duediligence report is the written summary of what the buyer's lawyers found,organized by review area and ranked by severity. A typical report opens with anexecutive summary and a red flag list, then covers each area (corporate,contracts, litigation, IP, employment, regulatory) with the documents reviewed,the issues found and a recommended action: a price adjustment, a specificindemnity, an escrow, a closing condition or walking away. Findings feeddirectly into the representations, warranties and indemnities in the purchaseagreement.

What is the difference between legal and financial duediligence?

Financial duediligence tests the numbers: quality of earnings, working capital, debt andcash flow, usually led by an accounting firm. Legal due diligence tests therights and obligations behind those numbers: whether the target owns its assetsand IP, whether its key contracts survive a change of control, what litigationand regulatory exposure it carries and whether its employment practices complywith the law. The two overlap on tax, leases and customer contracts, so bothteams should share one request list and one data room.

What are the red flags in legal due diligence?

Common redflags in legal due diligence include unclear ownership of shares or IP,material contracts that terminate or need consent on a change of control,litigation, government investigations, sanctions or export control exposure,lapsed permits, misclassified workers and unresolved harassment claims. Eachone can change the price, add a special indemnity or escrow or stop the deal.In BRG's 2026 M&A Disputes Report, earnoutsand representations and warranties were the contract terms most often at thecenter of 2025 disputes, so red flags should be written into those terms.

Avoid legal surprises 

The conclusion is simple: Conduct high-quality legal due diligence now to minimize the chances of unwanted legal liabilities after the transaction has closed.

The universe of legal issues in M&A is too complex to leave to chance. By conducting a thorough LDD, you give your acquisition its best chance to create ongoing shareholder value.