One of the complex and dynamic changes on the organisation level is Mergers and Acquisitions (M&As). M&As have been practiced since several decades for growth and expansion purposes. Recent developments in the frequency of M&As has drawn attention from researchers resulting in findings that more than half of the deals fails to achieve the aimed synergies. Solution to this problem could be to build preparedness to allow organisations to prepare for future or announced mergers in a way that enable faster pre-merger planning and smoother post-merger integration (PMI). In this article we will analyse M&A Preparedness building using a retrospective case study to a) demonstrate that the success of such strategic changes depends on several essential and largely overlooked factors, and b) outline a possible approach of building preparedness for M&As.