[unobatbayar]

I like OTP. But I fear when I change phone number or leave country, the next owner could literally login to any of my online accounts using OTP on my previous number. That's why I always remove it from every account when I update, but can't keep track of all my accounts or emails.

[e-clinton]

Don’t give up your main number. 10 years ago I changed phone numbers and ported my old one to a super cheap SIP line. 3 years later I grabbed it back and it’s been that’s my main number since.

I use SMS OTP for a lot of services which would have little consequence if hacked.. and leave things like email and other sensitive stuff to the apps generating tokens.

[unobatbayar]

That's true. My UK number seems to be completely fine after many years, even if I don't top it up. But some other country, after few months of inactivity they seem to be automatically sold to a new user.