This work aims to analyze the accounting and reporting protocols for company business combinations within the frameworks of the dominant accounting standards: IAS/IFRS and US GAAP. The analysis has revealed that, despite a substantial convergence of these standards, several distinct discrepancies continue to exist, in terms of definition of "control", assets and liabilities arising from contingencies, business definition, non-controlling interests, etc. This can bring to different accounting outcomes in relation to the used standard. Given the increasing frequency of cross-border business combinations, it is critical to minimize these differences. This work wants to be a useful instrument for practitioners and academics to identify the differences that can arise in a business combination accounting according to the two different standards. Riccardo Savio is Certified Public Accountant and Statutory Auditor. Riccardo Savio joined La Sapienza University as a Business Administration Researcher in 2021 after his postdoctoral tenure at LUMSA University. He earned a Ph.D. in Management from LUISS University and was a visiting Ph.D. scholar at SKEMA Business School. His research, focusing on accounting, financial statement analysis, and performance measurement, has been published in journals such as British Journal of Management, the International Review of Entrepreneurship, and the International Journal of Managerial and Financial Accounting.