WESCO INTERNATIONAL INC

Conclusion Regarding the Effectiveness of Disclosure Controls and Procedures

Under the supervision and with the participation of our management, including our principal executive officer and principal financial officer, we conducted an evaluation of our disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)). Based on this evaluation, our principal executive officer and our principal financial officer concluded that our disclosure controls and procedures were effective as of the end of the period covered by this report.

Management’s Report on Internal Control Over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting as such term is defined in Exchange Act Rules 13a-15(f) and 15d-15(f). Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate. Under the supervision and with the participation of our management, including our principal executive officer and principal financial officer, we conducted an evaluation of the effectiveness of our internal control over financial reporting based on the updated framework in Internal Control — Integrated Framework (2013) (2013 Framework) issued by the Committee of Sponsoring Organizations of the Treadway Commission on May 14, 2013. Based on our evaluation under the 2013 Framework, our management concluded that our internal control over financial reporting was effective as of December 31, 2025.

The effectiveness of the Company’s internal control over financial reporting as of December 31, 2025 has been audited by PricewaterhouseCoopers LLP, an independent registered public accounting firm, as stated in their report, which is included herein.

Changes in Internal Control Over Financial Reporting

During the last fiscal quarter of 2025, there were no changes in the Company’s internal control over financial reporting identified in connection with management’s evaluation of the effectiveness of the Company’s internal control over financial reporting that have materially affected, or are reasonably likely to materially affect, the Company’s internal control over financial reporting.

During the last fiscal quarter of 2025, the Company continued its multi-year, phased development and implementation of a new Digital and Data Platform (“DDP”). The DDP is intended to be a unified, technology-enabled operating model that spans all business functions, maintains and enhances the flow of financial information, and improves resource efficiency. The implementation, in certain cases, may affect the processes that constitute the Company’s internal control over financial reporting and will require testing for effectiveness.

The Company concluded, as part of its evaluation described in the above paragraphs, that the current quarter developments have not materially affected, or are reasonably likely to materially affect, its internal control over financial reporting and will continue to make such an assessment throughout the implementation period.