Authy manages security via two-factor authentication as a free service for anyone with a phone number. We also manage security for many partners who rely on our preventing unauthorized access to users' accounts. Locking an account with a phone number is serious business and due to recent hacking events publicized in the media, we cannot approve phone change requests immediately without doing some research.
For many, a big advantage of using Authy for two-factor is the ability to keep the app on a couple devices, so if you lose your phone or travel with your computer to a place without cell service, you can still access your accounts without any difficulty. Also, you may update the number immediately if you still have a device registered to the old number.
If you have changed your phone number without updating accounts you locked elsewhere using two-factor authentication, you are locked out. To help, we offer a security review service here to request updating the lock to a new number. During this time, our security system may attempt to verify ownership of the phone numbers through various means, and additional information may be requested from you to help verify your claim of ownership.
This information must be handled through the secure online form linked above - please don't send requests via email. We wouldn't want any information to be handled unsafely.
This is a sensitive process and sometimes not enough information is available to update the number. In such cases, you may attempt the phone change review again if you think your information was unclear or you have additional information to add. Another option will be to contact the support team of the Authy partner you are trying to access. You may be able to share transaction history or financial details with them, but ultimately it is up to their preference whether to allow access via email request, when the phone number is lost.