The success of any business merger or acquisition is not achieved in meeting rooms; it is achieved through strong people management and transparent, fluid communication. HR professionals are the key element that ensures these corporate moves become efficient and productive.

Madrid, November 24, 2025. Mergers do not fail because of strategy; they fail because of people. “Cultural conflicts, the loss of key talent, resistance to change, middle managers who do not embrace the new vision, or a lack of clarity around roles and leadership are the main issues that jeopardize a merger,” explains Álvaro Jiménez, COO and cofounder of Kaatch.co, the leading HR-as-a-service platform. “And it is the HR department that must act as the engine of integration,” he adds.

When two companies merge, a new institution is created. “This means bringing together two leadership structures, negotiating key roles, shaping a new shared identity, defining the values, norms, and processes of the new company, and restructuring teams with a focus on talent retention,” lists Emmanuel Djengue, CEO of Kaatch.co.

However, when one company buys another, “the relationship is no longer between equals. The acquiring company imposes its processes, culture, and leadership, and people from the acquired company may feel a loss of identity, resentment, or resistance to change,” he explains.

In both situations, the role of HR is critical, “and several studies by consulting firms such as McKinsey, BCG, and Deloitte agree that around 30% of failures in M&A are due to human and cultural issues rather than financial ones,” recalls Djengue.

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Why is HR key in M&A?

HR is not a support or administrative area; it is a strategic business actor. “The sooner companies understand this, the more efficient they will be in all processes and corporate transformations,” says Jiménez.

When two companies merge, “there are specific people management profiles that become essential for the success of this corporate move,” notes the Kaatch.co COO. He stresses that “talent management, cultural integration, communication and uncertainty management, and the design of the new structure, processes, and policies all fall on these professionals.”

In mergers and acquisitions, the real challenge is not the negotiation of the price or the search for financial synergies; it lies in the ability to integrate people into the new organizational structure. “When HR assumes a strategic role, the deal evolves faster, teams align with business objectives, and the promised synergies materialize,” says Djengue. “But when HR is neglected, the deal can fail, even if its financial fundamentals are impeccable.”

And what happens when there is no HR department?

Companies are defined by the professionals who make them up. “This is why, when there is no focus on managing these people and they are not told clearly about their new roles or place within the new company, they can become demotivated, resistant to change, or directly start seeking new opportunities,” points out the Kaatch.co CEO.

The most fragile scenario arises when two companies without HR departments decide to merge. “With no internal structure capable of handling issues such as talent retention, culture, communication, contracts, or change management, responsibilities fall onto the owners or management, who improvise decisions without the necessary expertise,” warns the Kaatch.co COO.

He also notes that when this happens “the consequences can include salary inequalities, conflicts due to unclear criteria, spontaneous staff turnover, and a climate of uncertainty that demotivates even the most committed employees.”

When only one of the companies lacks an HR department, “the balance immediately tips,” warns the Kaatch.co CEO. “Even if the official narrative speaks of a merger between equals, the organization that has HR structure in place will inevitably define the rules, processes, and culture.”

Outsourcing the HR function, even temporarily, “and creating within the first 90 days a minimal area dedicated to people, along with formalizing basic policies and contracts, can prevent the integration from becoming stuck,” notes Djengue.

When two companies join forces, attention usually focuses on the numbers. However, the true success of the move is determined in a less visible but far more decisive territory: people.