MPAN decoder
Paste the 21-digit electricity supply number from your bill and we’ll break it down into plain English — profile class, distributor, and a check-digit validation that confirms the number has been copied correctly.
What is an MPAN?
The Meter Point Administration Number (also called the supply number, S-number or “electricity 21”) uniquely identifies an electricity meter point in Great Britain. It travels with the property, not the supplier — so when you switch supplier, the MPAN stays the same.
The number is split into a top line (profile class, meter timeswitch code, line loss factor) and a 13-digit core (distributor, unique reference, sequence, check digit). This tool decodes both and runs the official prime-weighted check-digit calculation locally in your browser.
Where to find it
Look on any electricity bill or supplier portal for a panel labelled “Supply Number” or marked with a large S. It is laid out as a top row of eight digits and a bottom row of thirteen, often inside a thick grid. If you only have the bottom row, paste those 13 digits — the tool still works.
Send us one bill. We'll send back every overcharge — and the cheapest legitimate replacement.
Whether you run a Mayfair restaurant group or rent a flat in Salford, the audit is the same and the fee is the same: nothing, unless we save you money.