Electricity Meter Replaced? Preserve the Reading History Correctly

A replacement is a new register, not a lower reading

When an electricity meter is replaced, the new display often starts near zero or another opening value. If you enter that value into the old meter's uninterrupted history, software may calculate negative consumption or produce a false anomaly.

Create an explicit boundary between the physical devices.

Record the old meter before removal

Where safely possible, preserve:

• Old meter number
• Final visible reading and timestamp
• Removal date
• Provider work order, notice or reason
• Photograph of the visible face if permitted

Do not interfere with seals or the provider's work.

Record the replacement as a separate meter

For the new device, save:

• New meter number
• Opening reading
• Installation date and time
• Unit, decimal precision and multiplier
• Import/export or time-of-use registers when applicable

Archive the old meter rather than renaming it into the new one. Historical bills then remain attached to the device that produced them.

Reconcile the transition bill

A transition bill may contain a final old-meter segment, a new-meter segment, or an adjustment. Check whether the provider lists both serial numbers and readings. Do not manufacture one continuous cumulative number by adding the new opening reading to the old closing reading.

Consumption can be combined for a bill only when the provider's segments and multipliers support that calculation; the underlying readings should remain separate.

MeterPilot workflow

1. Add the final reading to the old meter.
2. Close or annotate its final billing segment only with confirmed information.
3. Mark the old meter inactive.
4. Add the replacement under the same property with its new identifier.
5. Enter the documented opening reading.
6. Treat the first few readings as a new baseline for anomaly detection.

Why this matters later

A clear boundary prevents negative usage, keeps reports auditable and explains why the property's cumulative sequence changed. It also helps when a provider later revises the transition bill or asks for the old device's final value.

A worked transition timeline

The new-meter interval is 73 − 6 = 67 kWh. There is no valid calculation of 6 − 48,920 because those values come from different physical registers.

Ofgem's replacement guidance requires old closing and replacement opening readings, dates and serial numbers in its scheme context; that is a sound evidence model even though your provider process may differ. See Replacing a meter.

Questions for the transition bill

• Does it show both old and new meter identifiers?
• Is there an unmeasured gap between removal and installation?
• Are both segments actual, estimated or adjusted?
• Did the provider apply a multiplier to either device?
• Did time-of-use or import/export register mapping change?

Keep the installation notice after the first correct bill. A later audit may need to explain why the property history has two independent cumulative scales.