I use Ting because it’s the only provider other than Fi that offers TOTP 2FA without SMS fallback. They wrote about their SIM swap policies here: https://help.ting.com/hc/en-us/community/posts/360030105653-...
https://www.t-mobile.com/support/plans-features/sim-protecti...
https://www.t-mobile.com/support/plans-features/account-take...
The document reveals that SIM card changes will now require either SMS verification from the customer or the credentials of two employees.
For banks that insist on doing SMS-based 2FA, I use a less well-known Google Voice number that only I know and don't give to my normal contacts. That number does nothing other than to receive 2FA codes, doesn't forward its messages and calls to any other numbers.
My reasoning is that it would not be trivial to guess the phone number from my account/name, and to guess my name from phone number (unless someone hacks into the bank's db, in which I'm in troubles anyways). Furthermore if someone was able to figure out that link, it would not be trivial to do SIM swap on Google Voice, it would not be trivial to attack the Google Voice app. Two or three stars have to line up for someone to sim-swap that GV number.
But some stupid bank go further to ban GV numbers. In which case I just don't bank with them.
I appreciate the responses. I'll probably go with Ting, but Efani is also interesting.
By the way, for anyone in my situation who wants to stay with Fi but not be signed in to a Google Account on their device, https://www.reddit.com/r/GoogleFi/comments/xzqd6v/what_does_... may be interesting.
Stop relying on your mobile number. I am not sim swappable because only my carrier knows my number. I don’t use the phone number of my SIM card for anything.
In fact I replace it every 90 days with a new one bought for cash (Mint prepaid) with a new number.
Some landline carriers allow text messaging.
So if you could find one that offered that, your best bet would be a landline + PIC freeze.
Telekom in Germany but I also use a secondary sim that is only used for emergencies and 2FA.
Efani
Google Fi is the absolute best solution to prevent against SIM swap attacks. Turn on Advanced Protection (g.co/advancedprotection) and it is damn near impossible.
Every carrier ultimately delegates access to store and call center staff that can remove any PIN, witches curse, or anything else they offer to add to your account. MVNOs are effectively riding on the same networks and if you phish a high enough level support person at the parent carrier they can be swapped as well.