An MPRN, or Meter Point Reference Number, is the unique reference that identifies a gas supply point at a property in Great Britain. It is tied to the property rather than the meter and is used when switching supplier or resolving a gas supply query.
In one line: An MPRN is the unique number identifying a property's gas supply point, attached to the address rather than the meter.
How an MPRN works
The MPRN, sometimes called the M number, is a numeric reference found on the gas bill. It identifies the gas supply point so the right meter and account details are matched when a customer switches or reports a problem.
When taking over a property or changing supplier, providing the MPRN ensures the new supplier connects to the correct gas supply rather than a neighbour's.
Because the MPRN belongs to the property, swapping the gas meter for a new one does not alter it.
MPRN vs MPAN
An MPRN identifies the gas supply point, while an MPAN identifies the electricity supply point at the same address. A dual-fuel household has one of each.
Both references stay with the property, so they are the identifiers used to arrange, switch or query supply for each fuel.
Primary source: Ofgem: Get help with energy