Pitney Bowes make franking machines. More recent ones use wifi direct to the internet or USB to a computer for top ups and balance verification.
Older machines use a telephone line. So have an RJ11 (square) connection at the back and then, in the UK, go to a BT plug on the other end of the lead.
BUT… it isn’t a standard lead. You can’t use the Pitney Bowes lead with a normal phone or fax machine and you can’t use a normal replacement lead from a shop with the Pitney Bowes Franking machine. FFS. Really?
So.. going from left to right as you look at the connectors (as shown in the picture above) where pin 1 is the left-most pin.
Pin 1 on the BT plug goes to pin 3 on the RJ11 plug
Pin 2 on the BT plug goes to pin 4 on the RJ11 plug
Pin 3 on the BT plug goes to pin 1 on the RJ11 plug
Pin 4 on the BT plug goes to pin 2 on the RJ11 plug
Seriously.. Every other lead for a telephone or fax machine is just a 1:1 mirror of the connections. Why bother being annoying and different Pitney Bowes!
Hope the above information helps someone if they are needing to splice up a new lead.