> The reason that you don't lose access to accounts when losing your MFA apps is that you took down the emergency backup codes and you committed them to paper, or some other durable medium, in a place where they can easily be accessed during a crisis. You did this scrupulously with each MFA activation, didn't you? Didn't you?
Not all TOTP implementations, especially indie PHP websites, are robust enough to have implemented backup codes.
Well, that's pretty sad, but surely, in every case, there is some procedure that's delineated for account recovery when something goes wrong?
I have been dismayed at some supposedly professional implementations, such as when I telephoned Wal-Mart to ask what can be done if I lost my phone (SMS is their only 2FA) and they said that they were prohibited from changing anything in account settings or profiles, and the best idea was to create a new account. (That is crazy -- if you shop at a marketplace like that, they've stored all your receipts, your membership, a potentially years-long trail of paperwork that you may need for taxes, or reimbursement, or refunds later on!)
Even worse, I had a bad time with the United States Postal Service. If I recall correctly, I'd lost access to the registered email address, and I was requesting to change it to something within my control, and they said "no can do", and they told me that my only recourse would be to create a new account, so that's what I did. Interestingly, USPS offers 2FA via either email or SMS, and their SMS gateway service is frequently out of order, so I always use email when logging in there.
Once, around 2021, I contacted GitLab to inform them that their account recovery process was a backdoor to circumvent MFA. They denied any such problem. I suggest that any account recovery implementation be just as secure as the front door to sign in, but also not impossible, because why do you want loyal customers to lose their accounts completely?
Not all TOTP implementations, especially indie PHP websites, are robust enough to have implemented backup codes.