Any network that isn't shared with your personal phone number. That is: if you have a dedicated number for SMS 2FA, it will show up in fewer places where the ha

Any network that isn't shared with your personal phone number. That is: if you have a dedicated number for SMS 2FA, it will show up in fewer places where the hackers might find it. It's easier to monitor for breaches, and replacing it is a simple matter of updating your accounts - no need to worry about lost contacts, friends, bills, etc. Although, "bills" reminds me - a lot of companies overload the use of 2FA SMS for both identification and 2FA purposes, not to mention most customer service centers expect the call to originate from the same number that receives 2FA SMS messages for authenticating to the account being serviced.