If you lose your mobile device, or if you cannot receive an authentication code with the authentication app or by SMS, you can log into Chatwork using a backup code. 

• Backup codes are provided when you set up two-factor authentication, but you can check them on the Two-Factor Authentication page any time.
• You can generate a set of 10 new backup codes any time.
• Once you use a backup code, it will be invalidated, so be careful.
• If you turn off two-factor authentication, the backup codes will all be invalidated as well. If you turn it on again, check for newly generated backup codes.

Checking backup codes

1. Access the Account Settings page via [Personal Settings] in the menu below [username] at the upper-right of the chat screen.
2. Access the Two-Factor Authentication page via [Two-Factor Authentication] in the menu at the left of the screen.
3. Click [Show] for a backup code.
4. Enter your login password in the password input field, click the [Next] button, and then you can check the backup code.