The SIM Card Resale Mechanism
By law, phone numbers belong to telecom operators, not subscribers. If there is no paid activity for three to six months, the number is canceled and put back on open sale: the new owner puts the SIM card into a smartphone and begins receiving notifications from banks, social networks, and marketplaces belonging to the previous user.
How to Protect Yourself When Changing Numbers
- unlink your old number from email boxes, banking services, messengers, and government portals in advance
- enable two-factor authentication via code generator apps rather than SMS
- set permanent cloud passwords on important accounts that must be entered in addition to the SMS code
- submit a request to your carrier to block and close your SIM card when you stop using it