Spam has been a massive problem through text messages over the last few years. Now, T-Mobile has changed its terms of service to add fines as high as $2,000 to third-party messaging accounts that send spam, social engineering messages, or illegal content over the T-Mobile network. These new fines wi...
Good luck getting all your 2FA changed on all your accounts. Good luck updating all your friends and family. Good luck informing every company you do business with.
Idk about 2FA, but updating friends and family is insanely easy on most messaging platforms. I can update my phone number and then WhatsApp or Telegram will prompt those who chat with me that I've changed my number and they can switch to that number for chatting.
WhatsApp:
Notice received when the number is changed on WhatsApp:
Telegram:
As for contacting businesses, this seems like a personal situation, since I contact companies via the above messaging apps. So they will receive a notification about my updated number.
I'll verify if this is optional, so we can choose if people get that notice...
Edit:
You can't specify who gets informed. If you've blocked someone, they will not get that notification.
I've also added images above to demonstrate how it works on the two platforms I mentioned.
I avoid this wherever possible, because the only reason to do it is to track you more. It's expensive and more complicated to set up than app 2fa which is free to operate.