Finding the serial number on the DM300M-DM475
The serial number, also referred to as the meter number, is the identification number registered with Royal Mail for the license of your franking machine.
The serial number is on a white sticker, located at back of the franking machine.
The Product Code Number (PCN) is the franking machine type.
The serial number (Meter #) is a 7-digit number, beginning 66....
UPDATED: 03 January 2023