M&A due diligence process for accounting firms: A 2025 guide
Mergers and acquisitions (M&As) are defining moments in a business’ journey.
Done right, M&A deals unlock new markets, service offerings, strategic direction, and access to a bigger, stronger team—fast-tracking firms towards their goals.
But only if it’s the right fit.
Between 70% and 90% of M&A deals fail, making them a high-risk business decision, but proper due diligence can maximize the chance of success and return on investment.
Whether you’re offering M&A services to clients, or you’re preparing your own firm for a merger or acquisition, here’s what you need to know about the M&A due diligence process.
What is the M&A due diligence process?
Before a merger or acquisition is finalized, both parties need to feel confident in their decision, which means they need answers to their most important questions.
What are the potential risks involved? How financially stable is the other firm? Can this transaction deliver real value and how can that be maximized?
The M&A due diligence process is a systematic investigation of a company’s financial, legal, tax, operational, and strategic position. It helps buyers understand what they’re acquiring and helps sellers present themselves with clarity and confidence.
The goal is to verify facts, surface risks, identify opportunities, and ultimately decide whether the transaction should proceed and on what terms in order to facilitate a graceful merger.
This process is essential whether you’re acquiring a competitor, if you’re the target company, merging with a peer, or advising a client through the same.
M&A due diligence process: Step-by-step guide
Below is a step-by-step due diligence checklist that can guide both in-house M&A pursuits and client-facing services, helping you make informed decisions that benefit all stakeholders.
Step 1: Evaluate goals
Start with alignment. What is the strategic purpose of this particular deal? Growth? Geographic expansion? Niche specialization? Understanding your objective will shape every part of the process.
Step 2: Consider strategic fit
The success of an M&A deal depends on more than the numbers. You need to understand how well the two businesses fit together in day-to-day operations and long-term direction. Here’s how to evaluate that compatibility:
Business model: Evaluate how each firm makes money, delivers services, and structures its operations.
Client segments: Analyze the types of clients each firm serves across industries, size, geographic reach, and client expectations.
Culture and values: M&A success is often determined by how well people align on work ethic, values, and employee experiences. Do both firms' synergies complement each other?
Leadership philosophy: The mindset and dynamics of leadership must also align across decision making styles, vision for the practice, and tolerance for change.
Tech stack: How compatible are both firms’ approaches to technology? Are they both progressive, or is one more traditional? This will make all the difference when it comes to the actual process of merging firms, and forms a critical component of IT due diligence.
Step 3: Analyze financials
Financial analysis is at the core of due diligence. It allows the acquiring firm to verify that the business is performing as advertised, ensure profitability, understand the company’s operations, and uncover any hidden liabilities, and evaluate the financial sustainability of the deal.
In accounting firm M&A transaction, the following are non-negotiable:
Review 3–5 years of financial statements: A comprehensive historical financial review helps establish patterns and detect anomalies. Key documents to request and analyze include income statements, balance sheets, cash flow statements, financial metrics, and other financial records.
Validate audit history and tax filings: Ensure all tax returns are filed and up-to-date, understand if the firm has been audited internally or externally, ensure regulatory compliance across sales tax, payroll tax, and corporate tax, and if there are any pending tax disputes or penalties.
Understand revenue breakdowns, profit margins, and recurring income: Firms with strong recurring revenue, low churn, and predictable margins typically command higher valuations.
Step 4: Examine all records
This stage moves beyond financials and into the operational DNA of the firm. You’re verifying that the firm is legally structured, has transferable assets, is free of any hidden legal issues or liabilities.
Corporate records
Start by validating the legal existence and governance structure of the firm:
Shareholder agreements: Understand ownership structure, voting rights, and how equity is distributed. Are there clauses that affect a sale, such as right of first refusal?
Board minutes and resolutions: Look for decisions regarding mergers, loans, legal disputes, or compensation. This offers insight into internal controls and strategic direction.
Business licenses: Ensure the firm is licensed in every jurisdiction it operates. Missing or expired licenses are red flags.
Articles of incorporation and bylaws: Confirm the firm’s registered legal structure (LLC, LLP, Corp, etc.), how it’s governed, and any obligations that could carry over post-deal.
Intellectual property
Verifying a firm’s intellectual property ensures you’re acquiring legally protected, transferable assets that contribute real value. This includes:
Trademarks: Ensure all logos, brand names, and taglines are registered and uncontested.
Copyrights: Understand the landscape of the firm’s custom content, guides, frameworks, or code written in-house.
Software licenses: Review contracts for platforms like Karbon, Xero, QuickBooks, or proprietary systems. Are they transferrable or tied to the original entity?
Internal IP: This could include proprietary spreadsheets, training materials, onboarding flows, trade secrets, or service models that have been productized.
Employee records
People risk is one of the most delicate and impactful parts of a merger. The goal is to ensure key members stay on, employee costs and obligations are fully known, and any disputes are transparent and resolvable. Things to be aware of include:
Contracts and benefits: Understand employee agreements (especially for senior staff and equity holders), non-compete clauses, benefits, and compensation structures.
Employee disputes: Are there any open or historical human resources issues? Wrongful termination claims? Harassment investigations? Has the firm ever been reported to labor boards or professional associations?
Litigation information
Understanding a firm’s litigation history reveals its risk profile, and provides additional insight into culture, integrity, and reputation. Here’s how to approach this component of your due diligence:
Request full disclosure of all legal matters: Including active lawsuits, settled disputes, arbitration or mediation proceedings, and any regulatory investigations or disciplinary actions.
Investigate the nature and frequency of disputes: Understanding what the firm has been involved in—and why—is just as important as knowing if they’ve been sued.
Step 5: Risk management
Risk management involves taking all the information you’ve learned above regarding financials, litigation, audits etc. and then analyzing the level of risk these findings bring to the deal.
It’s also important to analyze market risks, like shifting client demand, economic downturns, increased competition, and industry consolidation, as well as broader risks like cybersecurity concerns, and any specific risks related to the firms’ customer bases, like supply chain interruptions.
M&A failures can simply happen because risks were either underestimated or unmanaged. By identifying, quantifying, and proactively addressing key risks, you protect the value of the transaction and set the combined entity up for long-term success.
Step 6: Valuation
After gathering data across financials, operations, legal, technology, HR, and market position, it’s time to translate that information into a dollar amount that reflects the firm’s true value.
The goal is to develop a realistic, justifiable valuation that considers historical financial performance as well as future potential and identified risks.
Getting help from an experienced valuation expert ensures the price is fair, defensible, and grounded in a deep understanding of what truly drives value in an accounting firm.
Step 7: Final offering formation
Once due diligence is complete, valuation is agreed upon, and key risks have been identified and accounted for, it’s time to formalize the transaction. This is where all the insights gathered throughout the process come together into a clear, structured, and legally binding deal.
This step typically involves negotiation, documentation, and deal structuring, followed by the signing of contracts and planning for a smooth closing and post-merger integration.
Engage legal counsel: Hire an experienced attorney who specializes in the sale of accounting firms.
Create a non-disclosure agreement (NDA): Protect your most confidential information by having potential buyers sign an agreement to keep everything under wraps.
Put a letter of intent (LOI) in place: Outline the initial agreement and set preliminary terms and conditions with a non-binding LOI.
Write the purchase agreement: Include as many details of the arrangement as possible, such as preliminary terms, conditions, and disclaimers.
Finalize terms: Negotiate and sign a legally binding purchase agreement detailing sale terms, asset transfers, warranties, intellectual property, and non-compete information.
Your legal counsel should handle most of this process for you, facilitating a smooth transaction with your best interests at heart, and a calm post-acquisition or merger transition.
Essential documentation during the M&A due diligence process
Here’s a quick-reference checklist of required documentation:
Contracts and agreements
Incorporation and corporate documents
Financial statements and audit reports
Tax returns and filings
HR and payroll records
Insurance policies
IP and technology documentation
Litigation records
Regulatory licenses
Why is due diligence necessary for mergers and acquisitions?
Due diligence ensures transparency, mitigates risk, and informs negotiation. For acquirers, it prevents buying a liability. For sellers, it enables stronger positioning and valuation.
A comprehensive due diligence process supports smarter negotiations, smoother integration, reduced legal exposure, and stronger post-merger success.
Types of M&A due diligence
There are multiple types of due diligence, each essential in its own right:
Financial due diligence
Verifies financial health, growth potential, forecasts, and accounting practices.
Tax due diligence
Identifies past or upcoming tax liabilities, compliance gaps, and credits.
Legal due diligence
Surfaces legal risks tied to contracts, intellectual property, and litigation.
Commercial due diligence
Assesses market position, competition, and strategic outlook.
Operational due diligence
Looks at day-to-day workflows, business plans, systems, and human capital.
How Karbon helps accounting firms with mergers and acquisitions
Practice Marketplace by Karbon is a platform specifically designed for firm owners to connect and initiate accounting practice sales in a secure environment. They can list their businesses for sale, and potential buyers can browse, filter, and connect based on various criteria.
You can also connect with experts to optimize your workflow, gain advice on M&A, and tackle your biggest operational challenges.
If you’re putting in the work to get your firm in the best possible position for a merger either as a buyer or seller, accounting practice management software can help get you there faster and more efficiently.
Not to mention that a strong, united tech stack drives efficiency, and so tends to command higher valuations.
The right tool can also streamline the M&A process.
Victoria Peters, who helped lead the merger between Envolta and Gauvreau, credits both firms' similar tech stacks—centered around Karbon as the practice management tool—as a key component in making the transition much smoother.
“With Karbon everything is there. We can see history from long before the merge for either side, ensuring we can answer questions as a complete group with the complete picture,” says Victoria.
Discover how you can ensure your own sale is as smooth with the help of a consolidated and modern accounting tech stack with Karbon at the core: book a demo today.