Although carefully planned and negotiated to reduce the company's corporate tax rate and further its expansion into global markets, Pfizer's high‐profile plan for a $100 billion merger with UK‐based AstraZeneca in 2014 never took place. The proposed arrangement was based on a corporate inversion, whereby the headquarters of the American pharmaceutical giant would be moved from New York to London. A subsequent attempt at merger with Allergan of Ireland also never materialized. Both proposals were strongly criticized by the US Government, local communities, and various stakeholders, leading Pfizer to withdraw its plans and remain in the United States. The company's experience highlights some of the problems that can arise in even the best‐considered consolidations in the ever‐changing pharmaceutical industry.