Two-factor authentication in Bitrix24 is linked to a specific mobile device, where a one-time login code is generated. If you decided to change your device or you have lost your phone, you need to set up two-factor authentication again.
How to reconnect two-step authentication when you change phones
To connect a new phone, go to the profile page and click the Security button. Click on the My mobile device has changed button and set up two-step authentication again for the new mobile.
For security reasons, we recommend you to enable the Make two-step authorization mandatory for all users option in the account settings. In this case, only the administrator will be able to disable the OTP. If the option is disabled, any employee can disable the OTP.
If the employee's mobile is lost
If an employee cannot log in to the account, you should temporarily disable two-step authentication for him/her. Only the administrator can disable it.
The employee will be able to log in to the Bitrix24 account and reconfigure the OTP.
If the administrator cannot log into Bitrix24 account
If there are several administrators on the account, one of them should temporarily disable the two-step authorization for the colleague so that this person can log in and reconnect OTP.