Four hours ago, Platformer's Zoe Schiffer wrote on Twitter: Twitter will start charging for two-factor authentication SMS.

And yes it is official: You will have to pay for the privilege of using Twitter authentication. In fact, unless you start paying for Twitter Blue ($8 per month on Android, $11 per month on iOS) or switch your account to use a much more reliable authentication app or security key, Twitter it will just disable 2FA after March 20th.
Getting rid of SMS isn't a bad thing, as SIM swap hacks give and take these days. Twitter's Jack Dorsey was the target of this technique four years ago. You don't want someone accessing your accounts pretending to be you just because they stole your phone number.
Of course, that's how Twitter is trying to justify this change, but there's certainly a simpler reason: sending SMS messages costs money, and Twitter keeps making cuts. The company had phased out SMS even before Elon Musk took over.
Meantime as reported by Rachel Tobac, Twitter transparency data shows that as of December 2021, only 2,6 percent of Twitter users use 2FA, and 74 percent of those users used SMS as their method of sending 2FA codes.
