Troubleshooting an analogue phone connection on the DM300-DM475

Learn how to troubleshoot an analogue phone connection on the DM300c/DM400c/DM475c (G920, G925) and DM300M/DM400M/DM475M (G922).
Products affected:
DM300c™, DM400c™, DM475™ (G920)
DM300M™, DM400M™, DM475M™ (G922)


The franking machine fails to communicate with the Pitney Bowes server and gives an error message, for example:
  • "No dial tone"
  • "No carrier detected"
  • "No Modem Detected"
  • "Data Centre Phone Busy"
  • "Connection Lost"
  • "Connection Failed"


The franking machine is not connecting to the data center over an analogue phone line.


  1. We recommend that you switch to a faster, more reliable digital connection - visit
  2. To troubleshoot an existing analogue phone line connection - first check the number that the franking machine is dialling. See How to change the phone number dialled on the DM300, DM400 and DM475.
Note: The franking machine should be plugged directly into the wall. We should remove any phone line splitters, they can add noise to the line and it is best if the franking machine is not sharing a phone line.
  1. Make sure that the franking machine is connected to an active analogue phone line:
    • The franking machine can use the same connection as a fax machine or credit card reader, or other dedicated analogue phone line.
    • Unplug the phone cord from the back of the fax machine or analogue device.
    • Plug the end of the phone cord that was removed from the fax machine or analogue device directly into the franking machine.
  2. Check what kind of phone line you have:
    • The franking machine is designed to work with a true analogue phone line, such as a dedicated fax line.
    • A DSL line may work. If there are problems try adding a DSL filter, DSL filters can be purchased at an office supply store or acquired from the phone company.
    • Simulated analogue phone lines can be problematic. They will use a device to simulate an analogue line, reboot the device if you are having issues.
    • A T1 or VOIP line will not work with the franking machine.
  3. If you must press a key on your telephone to get an outside line (often 9 or 0), you may need to enter a "dialling prefix" on the franking machine. See How to add or remove the dialling prefix on the DM300, DM400 and DM475 for more details.
If you are unable to connect to the internet, ask your IT department or internet provider to check the internet settings before you contact Pitney Bowes. If you still need assistance, please use the Contact Us options below.

UPDATED: 14 August 2021