144 0001514429 XXXXXXXX LIVE 0000929008 WESCO INTERNATIONAL INC. 001-14989 225 West Station Square Drive Suite 700 Pittsburgh, PA 15219 (412) 454-2200 CHRISTINE WOLF Officer Common Morgan Stanley Smith Barney LLC Executive Financial Services

1 New York Plaza 8th Floor New York NY 10004

4685 1215830.59 48646230 11/11/2025 NYSE Common 11/10/2025 Exercised Shares Issuer N 4685 11/10/2025 Cash N Christine Wolf

225 West Station Square Drive Suite 700 Pittsburgh, PA 15219

Common 08/27/2025 2098 471882.16 Sales that were executed on November 11, 2025 are being reported on this Form 144 filed on November 12, 2025 given the EDGAR system was not accepting filings on November 11, 2025 in observance of the federal holiday. 11/11/2025 /s/ Christine Ann Wolf