At some point I'm going to be changing my mobile phone. I currently use a Lumia 950. Now, I use my phone for 2FA, some via SMS but some - like OCUK - via the authenticator app. As long as I keep my phone number, the SMS authentication will be fine, but I'm worried about the authenticator app issue. Suppose I have the perfect storm of replacing my phone when OCUK demands re-authentication? I'm probably worrying over nothing, but I'd like to be sure.