Every year, companies across every industry pursue mergers and acquisitions (M&A) as a strategy for accelerated growth, market expansion and innovation. But while the potential upside is enormous, so are the risks. In fact, research shows that 70 – 90% of M&A deals fail. 

So what separates the success stories i.e. Cisco’s acquisition of Splunk or the Raytheon-United Technologies merger, from infamous flameouts like AOL-Time Warner? 

The answer lies not just in financial forecasting or legal frameworks, but in the human side of change: Leadership alignment, cultural integration and communication. 

After interviewing executives behind major deals from Amazon, Microsoft, Nestlé and others, here’s what we’ve learned: Successful M&A is a discipline, not a gamble. Below are 10 best practices that help ensure M&A deals deliver value not just on paper, but in practice.

1. Start with Strategic Fit Clarity

Every deal should begin with one crystal clear question: Why are we doing this? Whether the goal is acquiring technology, expanding market share, or vertically integrating the supply chain, define the rationale early. Once aligned, use scenario planning to pressure test the strategy under future conditions. 

Lesson: A strong strategic foundation is your north star throughout integration.

2. Conduct Cultural Due Diligence

Culture clashes are among the top reasons M&A deals falter. Don’t treat culture as an afterthought. Leaders should assess it like you would any critical asset. Interview employees, conduct surveys and compare leadership styles, decision-making norms and values. If Company A is hierarchical and Company B thrives on autonomy, ignoring that friction invites failure. 

Lesson: Culture isn’t soft. It’s a hard driver of retention, engagement, and performance.

3. Involve Leaders Early and Often

Executives set the tone. Bringing in leadership from both sides during the early planning phase fosters trust, transparency and alignment. Set up a joint steering committee to guide decision-making, manage expectations and model collaboration. 

Lesson: Misalignment at the top turns into dysfunction at every level.

4. Align on KPIs (Not Just Financial Ones)

M&A success isn’t just measured in profit margins. Integrate both leading indicators (like customer satisfaction and employee engagement) and lagging indicators (like revenue and churn). Cultural metrics, such as trust, clarity and collaboration, belong in your dashboard too. 

Lesson: What gets measured gets managed and improved. 

5. Create a Shared Integration Playbook

Don’t wing it. Build a living document that outlines priorities, synergy plans, team structure and integration phases. Appoint a dedicated integration team with cross-functional leaders from both sides (not just finance and ops) and give them decision-making authority. 

Lesson: A good playbook makes chaos navigable and expectations clear. 

6. Value the People Behind the Product

The technology, IP, or customers you acquire are all powered by people. Identify key contributors at every level, not just executives, and treat them like assets instead of afterthoughts. Be thoughtful about titles, reporting structures and influence. Perceived demotions can lead to swift exits and lost institutional knowledge. 

Lesson: People don’t stay where they don’t feel respected or heard.

7. Appoint Culture Champions

Culture doesn’t blend itself. Designate trusted, well-respected employees from both organizations to serve as cultural bridge-builders. These champions help co-create shared norms and guard against an “us vs. them” dynamic. 

Lesson: Integration is more than logistics. It’s identity work. 

8. Communicate Transparently, Early and Often

Employees, customers, and investors all want to know what’s changing, why it matters, and how they’ll be affected. Build a communications roadmap for each audience. Equip middle managers, who will ultimately be your frontline influencers,with messaging, training, and support. 

Lesson: Communicate early. Communicate often. 

9. Integrate in Phases, Not All at Once

Not all teams need the same pace of change. Some functions may integrate quickly, while others require time and sensitivity. Preserve autonomy where needed, and offer platforms for feedback, questions and emotional support. 

Lesson: Respect the human pace of change. Change done with people lasts longer than change done to them. 

10. Monitor, Reflect and Refine Post-Close

Your deal isn’t done when the ink dries. Build feedback loops, track KPIs quarterly and adjust your integration plan as needed. Celebrate wins, highlight cultural success stories, and update your playbook based on real outcomes, not just projections. 

Lesson: M&A is a marathon, not a sprint. Integration is an ongoing practice. 

The companies that succeed most consistently in M&A don’t treat it as a one-off. They build and refine internal playbooks that embed these practices into every stage of the deal. The goal isn’t perfection, but rather repeatable excellence that’s grounded in strategy, empathy, and execution. 

Whether you’re approaching your first acquisition or preparing for your fiftieth, these best practices can help transform a high-stakes transaction into a sustainable growth story.