FRITZ!Box 7490 Service - Knowledge Base

FRITZ!Box 7490 Service

Since updating FRITZ!OS, an IP telephone cannot be registered

Since updating FRITZ!OS, registration of an IP telephone or telephony app with the FRITZ!Box fails. The Internet telephone number configured in the IP telephone or app is not registered. An exclamation point is displayed under "Telephony > Telephony Devices" in the FRITZ!Box user interface for the respective telephone.


  • The password for registering an IP telephone must have at least eight characters. The IP telephone was disabled because the password was too short.

1 Changing the password in the FRITZ!Box

  1. Click "Telephony" in the FRITZ!Box user interface.
  2. Click "Telephony Devices" in the "Telephony" menu.
  3. Click the button (Edit) for the respective IP telephone on the "LAN/WLAN" port.
  4. Enter a password that is at least eight characters long and not the same as the user name.
  5. Click "OK" to save your settings and confirm that the procedure may be executed on the FRITZ!Box, if you are asked to do so.

2 Changing the password in the IP telephone

  • Enter the new password in the IP telephone for the respective Internet telephone number.