There are so many reasons why M&A integrations can fail, from inaccurate data, insufficient involvement by top tier leadership, limitations on resources, lack of long term planning, and a host of many others.

Why do so many mergers fail?

That's on the low end of how many mergers and acquisitions (M+As) are likely to fail. ... Basic reasons frequently cited for such a high failure rate include an uninvolved seller, culture shock at the time of the integration, and poor communications from the beginning to the end of the M+A process.

Why do some acquisitions fail?

Acquisitions fail because they are distracting. They often are not part of a company's core competence. Integration can be slow, and expensive. Identifying what your company will have to put in to the deal, not just what it will pay to close the deal, can be the difference between success and failure.