Notice an unexplained service change
A sudden loss of calls or messages, together with a notification that your number was activated on another device, can indicate a SIM swap. Service disruption alone has other explanations, so verify the change with your carrier.
Contact the carrier through a known route
Use the provider?s official support details to ask whether a SIM or account change occurred. Do not rely on a number supplied by someone who contacted you about an alleged security incident.
Understand the risk to sign-in codes
A person controlling a transferred number may receive text verification codes. This can put other accounts at risk when combined with stolen credentials. Review important accounts using their official apps or websites.
Strengthen the account boundary
Ask your carrier about account PINs and transfer protections. Where supported, consider an authentication app or security key instead of relying only on text messages. Keep recovery options under review and limit publicly shared personal details.