Smart meter SMETS2 capability

What a second-generation smart meter can measure and communicate, what separate setup is needed for smart tariffs and export, and what happens when communications fail.

SMETS2 means the second-generation Smart Metering Equipment Technical Specifications used in Great Britain. It describes the meter and associated equipment needed for interoperable smart metering. In practical terms, a SMETS2 installation is intended to communicate through the national network run by the Data Communications Company, rather than through a system tied to the supplier that first installed it.

That makes supplier switching more reliable, but “SMETS2” is not a guarantee that every service is working. The meter may be capable of recording import, export and half-hourly data while communications, account setup, an export MPAN or a particular tariff is still missing.

The parts of a smart-meter installation

A typical installation contains several devices with different jobs:

the electricity meter measures electricity imported and exported at the grid boundary
the gas meter, where present, measures gas use
the communications hub links the meters to the secure wide-area network and usually provides the home-area network
the in-home display receives data over the home-area network and presents consumption and cost information

The wide-area network, or WAN, is the route used by authorised industry parties. The home-area network, or HAN, is the short-range connection within the property. A weak WAN can prevent remote readings while the meter and display continue to work locally. A HAN fault can stop the display updating even though the supplier is still receiving readings.

These distinctions help diagnose faults. Replacing an in-home display will not fix a WAN problem, and a healthy display does not prove that the supplier has usable half-hourly data.

SMETS1 and SMETS2

Many first-generation SMETS1 installations originally used supplier-specific communications. Some lost smart functions after a switch. Large numbers were subsequently enrolled into the DCC network, so it is no longer accurate to assume that every SMETS1 meter is “dumb” or must be replaced immediately.

SMETS2 equipment was designed for the shared DCC arrangement from installation. Its main practical advantage is interoperability across suppliers, not the mere existence of a half-hourly register. A working enrolled SMETS1 meter can also support automatic and half-hourly readings.

The actual operating state is defined by:

whether the meter is enrolled on the DCC network
whether it is communicating in smart mode
whether the current supplier can retrieve the required import and export data
whether the intended tariff accepts that meter and data path

Import, export and half-hourly records

SMETS2 electricity-meter requirements include cumulative active-import and active-export registers and interval records. Government material describes storage of at least 13 months of half-hourly consumption data and at least three months of half-hourly export data.

For a property with solar or battery storage, the boundary between the home and grid is what the meter sees:

import is electricity entering the property from the grid
export is electricity leaving the property for the grid
solar used within the property never passes through the export register
battery charging and discharging can change both figures, but the meter does not identify which device caused the flow

The meter can measure net flow at the boundary; it does not measure total PV generation. A separate generation meter or inverter record is needed for that. Nor does the smart meter normally control the inverter, battery, EV charger or heat pump.

A meter can be recording export even when the local display does not make the export register easy to find. Conversely, a visible export register does not prove that an export MPAN and payment account have been set up. Ask the export supplier to confirm both the register and the remote data flow.

Smart tariffs need more than capable hardware

SMETS2 supports time-related consumption and tariff information, but modern tariff calculations may also take place in the supplier’s systems. The important customer-facing question is whether the supplier receives complete readings at the interval required by the contract.

For a time-of-use import tariff, confirm:

the tariff is active on the correct import MPAN
the account start date and clock treatment are recorded
half-hourly readings are arriving without persistent gaps
the supplier’s bill applies the right price to each period
the in-home display’s cost figure is suitable for that tariff

The display’s pounds-and-pence estimate can lag or misrepresent a complex or dynamic tariff even when its energy reading is sound. Use the supplier’s bill or tariff data for financial checks rather than treating the display as the final calculation.

For export under the SEG (Smart Export Guarantee), the installation needs a meter capable of taking half-hourly export measurements. It also needs a separate export MPAN and acceptance by an export supplier. None of those administrative steps is created automatically by fitting a SMETS2 meter.

Recording is not the same as communicating

A smart meter can continue registering cumulative energy when remote communications fail. It also retains interval history for a limited period. That makes recovery after a short outage possible, but it is not safe to assume that every missing reading will later arrive.

Data may be absent because of:

WAN coverage or communications-hub faults
the electricity meter losing its HAN link to the hub
incorrect meter, MPAN or register details in industry records
failed retrieval, validation or processing by the supplier
an account or tariff that has not been configured for the requested interval

If a supplier asks for manual readings, photograph the meter serial number and the relevant cumulative registers. Manual totals can help correct overall consumption, but they cannot reconstruct exactly when energy was imported or exported. That can matter on a half-hourly tariff.

Report the fault to the energy supplier, not DCC. DCC operates the network but does not manage the customer’s bill or meter account. Ask the supplier to confirm whether the meter is in smart or traditional mode and what recovery action it has opened.

Current communications replacement programme

The communications network is itself being renewed. This is a live programme, so its dates should not be treated as permanent product characteristics.

As at 22 July 2026, the current government and DCC position is that:

2G and 3G services used by many communications hubs in central and southern Great Britain are being replaced by a 4G service
service arrangements provide a path towards 2033, but suppliers must plan replacements before the relevant communications service ends
a SMETS2 installation can normally retain its meters and have the communications hub exchanged
remaining SMETS1 equipment with an integrated older communications arrangement may require full meter-system replacement
the long-range radio system used in the north is a different network and is not the same as the central and southern 2G/3G service

Do not request a speculative meter replacement solely because the existing hub uses an older network. The supplier should identify the actual asset and plan the appropriate exchange. Equally, do not ignore a formal replacement notice where continued smart operation depends on it.

Data access and privacy

The DCC network is a closed communications system rather than the household’s internet connection. DCC says it uses layered encryption and that names, addresses and bank details are not stored on the smart meter.

Energy-consumption data can still be personal data. Access is controlled through energy-sector rules as well as UK data-protection law. The domestic default for half-hourly sharing depends on the installation date and any later switch or new contract, not simply on whether the meter is SMETS2.

For the detailed current choices, see GDPR and energy data. A customer can also authorise a suitable third-party service to access data, but a battery or charger cloud account is separate from access through the regulated smart-meter system.

The in-home display and consumer access devices

The in-home display receives local data over the HAN. Government material says electricity consumption and tariff data can be made available at least every ten seconds on that local network. That is different from the half-hour settlement intervals and from the timing of supplier retrieval.

A compatible consumer access device can also use the HAN to provide data to another app or service. Compatibility, onboarding and data retention depend on the particular device and service. It should not be assumed that every Wi-Fi energy monitor is reading the regulated meter or that it can submit readings for billing.

When moving home, leave the meter and supplier-provided display at the property. Do not hand over a personal app account. Remove third-party access, export any data you need and follow the service’s ownership-transfer process.

What SMETS2 does not prove

Finding “SMETS2” in an account or meter description does not by itself prove that:

the meter is communicating
half-hourly readings are complete
export is enrolled or being paid
an in-home display shows a complex tariff accurately
a charger, battery or heat pump is compatible with a supplier’s managed service
the property is being billed from actual rather than estimated data

Check the function needed, on the relevant MPAN, with the supplier responsible for it.