Your MPAN is your Meter Point Administration Number — a 21 digit reference number used to uniquely identify your electricity supply point (the property where the energy is supplied to). This is also called a "supply number". Usually, your supplier will only need the last 13 digits of this number.
Your MPRN is your Meter point Reference Number — the same thing as the MPAN, except for gas, not electricity. MPRN numbers are 10 digits long. This is also sometimes called your "M number". Your supplier will need the full number for this.
Your MPAN and MPRN numbers can be found on your bills — the MPAN is visible in the box marked "S", and the important 13 digits take up the right hand side of the bottom row.
Your physical meters are unique, and each of them will have a Meter Serial Number, or MSN. This will be printed on your meter, usually near the display. Sometimes your MSN (or MSNs) will also be printed on your bill, usually just above the meter reading breakdown.
Your supplier needs to know these numbers, because they're needed to ensure the correct supplies are switched.
Sometimes, there are discrepancies between the number on these bills and the numbers on the National Database, or there isn't a number on the Database for the supplier to find, which can cause delays to your switch. If this is the case, the supplier will contact you — and us, via our proxy e-mail facility.
We'll usually be able to submit your MPAN and MPRN straight away on your behalf, but for meter serial numbers, we might need to contact you and get photos of your meters.
Once these numbers have been submitted to the supplier, your switch will continue normally.