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Configuring the integrated fax function in the FRITZ!Box

You want to use the FRITZ!Box to send and receive faxes? ✔ Simply set up the integrated fax function, you don't need a fax machine.

With the FRITZ!Box you can also send and receive faxes without an external fax machine. The FRITZ!Box receives the faxes and forwards them as PDF files named after the reception date and time via email and/or saves them on a USB storage device in a folder of your choice or under "FRITZ\faxbox". When sending faxes, you enter the text of the fax in the FRITZ!Box user interface. Received and sent faxes are displayed in the fax journal in the user interface in the menu "Telephony > Fax".

Requirements / Restrictions

  • A maximum of ten A4 pages can be transmitted per fax. If your fax document is longer, it will be shortened to ten A4 pages. If you append a graphics file, page 10 is reserved for the graphics.
  • Graphics can only be attached to the fax document if you are using Google Chrome or Mozilla Firefox. For technical reasons, you cannot attach image files with the Internet Explorer and Safari.
  • You can attach one image file saved in JPG or PNG format. Other file formats (such as PDF or DOC) are ignored when sending faxes.
  • Images larger than A4 are reduced in size when the fax is sent. Smaller images are centered.

1 Enabling fax transmission with T.38

If you use an internet telephone number for faxing, you must enable T.38 (fax over IP) in the FRITZ!Box for fax transmission. With T.38, a special network protocol is used for fax transmission instead of signal tones. This makes transmission significantly less susceptible to interference:

  1. Click "Telephony" in the FRITZ!Box user interface.
  2. Click "Telephone Numbers" in the "Telephony" menu.
  3. Click on the "Line Settings" tab.
  4. Click "Changing the Settings" in the "Telephony connection" section.
  5. Enable the option "Fax transmission using T.38".
  6. Click "Apply" to save the settings.

2 Configuring the fax function

Enabling the fax function and entering fax ID

  1. Click "Telephony" in the FRITZ!Box user interface.
  2. Click "Telephony Devices" in the "Telephony" menu.
  3. Click the "Configure New Device" button.
  4. Select the option "Fax function" in the section "Integrated in the FRITZ!Box" and click "Next".
  5. In the "Fax ID" field, enter the ID that should be transmitted to anyone who sends a fax to the FRITZ!Box, and that should be transmitted to recipients when sending faxes. You can enter your number or your name, for example.

    Important:Many recipients block faxes from numbers without caller ID to protect themselves from unwanted advertisements.

Selecting email forwarding and location for saving

  1. Select email forwarding and specify where faxes should be saved.
  2. If you want faxes that are successfully sent or received to be forwarded automatically to one or more email addresses, enable the option "Forward by email". If you want to enter several email addresses, separate them by a comma and do not add spaces between them.


    • If you enabled email forwarding, you can enable the option "Do not save". However, note that sent and received faxes are then not displayed in the fax journal in the user interface in the menu "Telephony > Fax". In addition, received faxes are lost and the fax function is deactivated if a fax is not successfully forwarded as an email. This way, senders do not receive positive transmission reports for faxes that are lost. The fax function is re-enabled when emails can be sent again or the FRITZ!Box is restarted.
    • Enable the option "Save internally" if you want faxes to be saved to the FRITZ!Box's internal memory.
    • Enable the option "Save on the USB storage medium" if you want faxes to be saved on a USB storage device connected to the USB port on the FRITZ!Box. The FRITZ!Box then saves the faxes on the USB storage device under "FRITZ\faxbox". After you set it up, you can select a different folder for saving them in the menu "Telephony > Fax > Settings". If you want to remove the USB storage device or enable the USB remote connection, you must disable saving to the USB storage device first. Otherwise, you will experience errors when receiving faxes because they can no longer be saved.
  3. Click "Next".

Entering email account information

In the next step, you may be asked to enter various email account information. This information is required if you want the FRITZ!Box to forward new faxes via email and the push service has not been configured yet. Enter the email account information as follows:

Note:The email account information can be edited any time under "System > Push-Service > Sender" in the FRITZ!Box user interface.

  1. Enter the password for your email account.
  2. Enter your username.
  3. Enter the name of your email provider's SMTP server and enter the port used by the SMTP server.

    Note:Outgoing emails are sent via the SMTP server (SMTP = Simple Mail Transport Protocol). Your email provider can give you the name and port number of the SMTP server.

  4. Enable the option "This server supports a secure connection (SSL)" if your provider supports SSL encryption.
  5. Click "Next".

Assigning telephone numbers

  1. If you want to send and receive faxes, enable the option "Send and receive faxes" and enable at least one telephone number to send faxes with. The number or numbers are then also used to receive faxes.
    • If you only want to receive faxes, you have two options:
      1. Either: Select one or more telephone numbers. Then the fax will accept all calls to these numbers and faxes are received automatically.
        • Or: If you do not select a number, automatic fax recognition will be used for fax reception. For fax recognition to work, a FRITZ!Box answering machine must answer the call. Configure the answering machine so that it accepts calls after 10 to 25 seconds. The greeting delay may not be too long because incoming fax calls would hang up then. Do not select the operating mode "Greeting only". With this operating mode, the time interval is too short fax recognition. The recording will be discarded after it recognizes a fax call.
    • If you only want to send faxes, enable the option "Send faxes only" and enable at least one telephone number to send faxes with.
  2. Click "Next" and then "Apply" to save the settings.

    Note:If you accept a fax call with a telephone connected to the FRITZ!Box, simply forward the call to a FRITZ!Box answering machine. The answering machine will automatically forward the call to the integrated fax machine after recognizing it as a fax call.

3 Using several email addresses for fax reception

If you selected several telephone numbers for receiving faxes, you can assign each of these telephone numbers a different email address to which faxes are then forwarded:

Note:Faxes that are forwarded from a telephone connected to the FRITZ!Box to an answering machine are forwarded to the email address(es) assigned to the first fax number.

  1. Click "Telephony" in the FRITZ!Box user interface.
  2. Click "Telephony Devices" in the "Telephony" menu.
  3. Click the (Edit) button for the fax function.
  4. Enter the email addresses for the various telephone numbers in the section "Fax Reception".
  5. Click "OK" to save the settings.