Abstract: Since 2011, the United Kingdom has prohibited all deal protections—including termination fees—in mergers and acquisitions (M&A) deals. We examine the effect of this regulatory change on deal volumes, the incidence of competing offers, deal-jumping rates, deal premiums, and completion rates in the United Kingdom relative to the other European Group of 10 (G-10) countries. We find that M&A deal volumes in the United Kingdom declined significantly in the aftermath of the 2011 reform (in absolute terms and relative to deal volumes in other European G-10 countries). We find no countervailing benefits to targets’ shareholders in the form of higher deal premiums or more competing bids. Completion rates and deal-jumping rates also remained unchanged. Our results suggest that deal protections provide an important social welfare benefit by facilitating the initiation of M&A deals.