Key answer
The MPAN identifies the supply; the serial number identifies the meter
For electricity supplies in Great Britain, the MPAN or Supply Number identifies the metering point connected to the network. The meter serial number identifies the physical device, while the meter reading is the changing consumption value. Check all three when matching a bill to a meter.
Illustrative supply number
How a full MPAN is laid out
Example format only — it is not a live supply number. The bottom row is the 13-digit MPAN Core most forms ask for. The full printed supply number also includes the eight digits above it.
Identifies the electricity supply point. Find it on a bill or supplier account; it is not normally printed on the meter face.
Identifies the physical meter. Match this number on the meter with the serial number shown on the bill.
The cumulative consumption value, usually shown in kWh. This changes as the business uses electricity.
Practical checklist
Take a usable meter reading
Supplier instructions differ by meter model. These checks reduce the chance of sending a reading from the wrong meter or missing a second register.
- 1Match the meter first
Compare the serial number on the meter with the bill. At a multi-unit site, do not rely on a handwritten unit label alone.
- 2Wake or cycle the display
Use the meter buttons only as directed. Look for a value labelled kWh, Total, Import or a numbered rate/register.
- 3Record every billed register
For a multi-rate meter, note each register and its label. Copy the digits exactly; follow the supplier’s instructions on decimal or red digits.
- 4Add evidence
Photograph the display and serial number where safe, then record the date and time. Keep the image until the next accurate bill arrives.
- 5Check the next bill
Confirm it says actual or customer reading, not estimated, and that the opening and closing readings follow on sensibly.
Meter types
Smart, advanced and half-hourly do not mean the same thing
| Term | How the data is obtained | What it means for a business |
|---|---|---|
| Traditional meter | A person normally records the display or dials. It may have one register or separate day, night or time-band registers. | Common on older, lower-consumption supplies. Bills can be estimated if the supplier does not receive a current reading. |
| Smart meter (SMETS) | Records consumption in short intervals and can send data through the national smart-meter communications system when operating in smart mode. | Generally associated with homes and smaller non-domestic sites. It can still be read manually from the meter display. |
| Advanced / AMR meter | Stores interval data and allows remote access. Electricity data is commonly recorded every half hour. | Widely used at larger or more complex business sites. The communications route and data service can differ from SMETS. |
| Half-hourly supply | Consumption is collected or used for settlement in 30-minute periods rather than only as a periodic cumulative total. | This describes the data and settlement arrangement, not one particular make of meter. It may involve capacity and metering charges. |
Important: a meter can be capable of recording half-hourly data without the retail tariff charging a different price every half hour. Ask separately about the meter, the settlement arrangement, access to interval data and the tariff.
Where to find the MPAN
Look on the electricity bill, annual statement or supplier account for a box marked Supply Number, S Number or MPAN. The full legacy format has 21 digits: eight on the top row and a 13-digit MPAN Core on the bottom row. Many forms ask only for that bottom-row core.
The MPAN is attached to the supply point, not simply to the meter casing. Replacing the physical meter does not normally create a new MPAN. A site can also have more than one MPAN, and premises with generation may have separate import and export arrangements. Never assume the first number you find covers the whole site.
- Confirm the supply address beside the MPAN.
- Use the 13-digit core when a form asks for the core MPAN.
- Keep the full supply-number box when a supplier asks for meter technical details.
- Treat account numbers, invoice numbers and meter serial numbers as separate identifiers.
Check that the bill belongs to the physical meter
Start with the supply address and then compare the meter serial number on the bill with the number printed or engraved on the meter. At a multi-unit building, labels can be wrong or out of date, so a serial-number match is stronger evidence than a handwritten unit name.
Next compare the reading on the meter with the latest closing reading on the bill, allowing for usage since the bill date. If the bill says estimated, the number may not match closely. Record a dated photograph and ask the supplier to confirm the registered MPAN and serial number when the evidence conflicts.
Single-rate, multi-rate and maximum-demand displays
A single-rate meter normally has one cumulative import register. A multi-rate meter has two or more registers for different time periods; the display may label them Rate 1 and Rate 2, day and night, or with other tariff-specific names. Record every register and its label rather than adding them together unless the supplier tells you to.
Larger supplies may show maximum demand, reactive energy, export or other technical values as well as imported kWh. These are not interchangeable with the billing reading. Use the supplier or meter operator's model-specific instructions when the display is unclear.
Accessing smart or half-hourly consumption data
A remotely read meter can provide more than a single cumulative number. Ask the supplier what interval data is available, which time zone it uses, whether values are actual or estimated and whether the file covers every half hour. Government guidance says non-domestic customers and their nominated third parties can request free access from the supplier to up to 12 months of historic smart or advanced meter energy-use data.
Use interval data to find overnight baseload, operating peaks and differences between weekdays and weekends. For procurement, send a consistent date range and note closures, new equipment or changes in opening hours so a prospective supplier does not treat an unusual year as normal.
- Ask for CSV or another reusable format, not only a chart.
- Check for missing or repeated intervals.
- Keep the MPAN and date range with the data file.
- Do not assume half-hourly settlement means a time-of-use retail tariff.
What Market-wide Half-Hourly Settlement changes
Great Britain is migrating electricity meters to Market-wide Half-Hourly Settlement. Elexon currently lists 7 May 2027 for completion of meter migrations and 2 July 2027 for cutover to the shorter settlement timetable. Migration changes how industry settlement uses consumption data; it does not by itself replace the meter, change the retail tariff or guarantee a lower bill.
During the transition, older profile-class shorthand is less reliable as a complete description of a supply. Ask the supplier to confirm the meter type, current settlement arrangement, data access and any tariff time bands rather than inferring everything from the first two digits of an older full MPAN.
Who to contact when something is wrong
Contact the supplier first for an incorrect bill, estimated readings, a meter that is not communicating or a mismatch between its records and the physical meter. The supplier can involve its meter operator or data service where necessary. Contact the local distribution network operator for a network fault, power cut or supply-point issue that the supplier directs to the network.
MPAN terminology in this guide applies to England, Scotland and Wales. Northern Ireland operates in a separate electricity market and uses different registration arrangements, so check the identifier and process with the Northern Ireland supplier or network operator.
- Keep bills, contract documents and dated meter photographs.
- Write down every affected MPAN and meter serial number.
- Record when the issue began and whether the site was occupied.
- Ask for the supplier's explanation and correction in writing.
Sources
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Next step
Now check the rest of the bill
Use the MPAN and meter reading alongside the rates, dates and tax lines on the invoice.