Effective June 1, 2021, Symantec changed the sender 'from' number for voice-generated security code delivery from +1-773-243-0399 to +1-669-223-0136.
Only the sender number changed; all other aspects of sending security codes by a voice call have not changed. The short-code and sender numbers for SMS are not changing.
Users should allow the number 669-223-0136.
Important: Put your protection first! Never enter a security code or any other personal information into a suspicious or unrecognized website. If you have any questions or concerns, please reach out to your organization's internal helpdesk or VIP administrator.