What is a SIM swap and what might it explain?¶

A SIM swap moves a mobile subscription and number to another SIM or eSIM profile. It can be legitimate replacement, or an unauthorised transfer enabling another person to receive calls, messages and authentication codes.

The number can leave the original handset¶

The victim may retain their phone while it loses service, and the new SIM becomes active elsewhere. That can explain account recovery or takeover events despite physical possession of the original device.

Build a timeline of last legitimate service, interruption, provider contact, SIM/eSIM activation, security messages and later logins. Preserve old and new SIM identifiers, subscriber-service and customer-contact records where available.

Test competing explanations and scope¶

Device failure, legitimate upgrade, account closure and number porting can produce similar symptoms. A SIM swap supplies control of the number, not automatically email, device sessions or every messaging account.

Establish what the transfer enabled, which codes or communications were received and who controlled the replacement access route.