Meter serial number / MSN

A meter serial number (MSN), sometimes called a meter ID, is the reference printed on a gas or electricity meter that identifies that physical meter. In Great Britain it is usually a mix of letters and numbers and is shown both on the meter, normally near the barcode, and in the supply details on bills or online account pages. Because it belongs to the meter rather than the property, the meter serial number changes when the meter is replaced, for example during a smart-meter upgrade. This makes it different from an MPAN for electricity or an MPRN (Meter Point Reference Number) for gas, which identify the supply point and stay the same when the meter or supplier changes. It is used to confirm that the correct meter is recording usage, such as checking the number on the meter against the number on a bill, and it can help identify a meter when registering, moving supplier or arranging export metering. It is not the supplier account number, the tariff, proof that a bill is accurate, an export MPAN, SEG registration or DNO approval.