What Is a Smart Meter and How Does It Work?

At a glance

  • A smart meter records energy use and can send readings automatically to your supplier.
  • The meter and the portable in-home display are different devices. A display fault does not necessarily mean a meter fault.
  • The national smart-meter network in Great Britain does not rely on your home Wi-Fi.
  • Smart meters can improve visibility and access to tariffs, but they do not guarantee lower bills or eliminate every billing error.

Smart metering changes how readings reach a supplier and how you can view consumption. It does not remove the need to understand the tariff or check an account. This guide mainly describes Great Britain’s national system; Northern Ireland has different arrangements.

On this page

The meter, communications hub and display

The electricity or gas meter measures the energy supply. A communications hub connects compatible equipment to the smart network. A portable in-home display shows information such as recent use and estimated cost.

The display is not the billing meter. Moving it, unplugging it or finding its screen blank does not automatically mean the meter has stopped measuring. A supplier’s app is another way of viewing data, rather than a replacement for understanding what the meter records.

The government’s household smart-meter guide explains the main components and installation process.

How readings reach the supplier

When operating in smart mode, the system sends readings through the smart-meter network. It does not depend on the customer’s household broadband connection.

The network operator, Smart DCC, explains why a smart meter does not need home Wi-Fi. A supplier app still needs an internet connection on the device used to access it; that is separate from the meter’s communications.

Coverage or equipment problems can interrupt automatic readings. The electricity supply itself need not stop because smart communications fail.

What smart mode means

Smart mode means the supplier is receiving readings automatically. If communications fail, a meter can continue recording while the supplier loses access to automatic data.

Check the readings and dates on actual bills. If they are estimated, ask the supplier why and whether a manual reading is needed. Ofgem explains smart-mode problems and advises contacting the supplier.

Do not assume that a working display proves everything is reaching the billing system, or that a failed display means everything has stopped. These are separate checks.

Will a smart meter reduce your bill?

A meter does not reduce an appliance’s energy requirement by itself. It can help you identify patterns and replace estimates with better information. Savings depend on what that information enables you to change and the tariff you use.

For example, a display may reveal a regular rise in demand when an immersion heater operates. Checking the schedule could explain the consumption. The saving comes from a suitable change to use or controls, not simply from installing the meter.

Compare kWh over representative periods, allowing for weather and occupancy. A change in the displayed pounds can result from a new tariff rather than a change in consumption.

Understanding the in-home display

A display may show instant electricity demand, cumulative consumption and an estimated cost. Check which fuel and time period it is displaying. Gas information may update less frequently than electricity information.

Its tariff information can be out of date, and the displayed cost may not reconcile with every account adjustment. Use it to understand patterns; use the bill and supplier records to check the account balance. See the Centre for Sustainable Energy’s explanation of energy monitors.

If the display is not working, follow the supplier’s troubleshooting instructions. Government guidance distinguishes display and meter problems. Do not remove covers or interfere with the meter or communications hub.

Tariffs, switching and new technologies

Smart meters can support tariffs with prices that vary through the day. Those tariffs may suit some patterns of use, but cheaper periods do not automatically make the whole tariff cheaper. Check peak rates, standing charges and whether you can move consumption safely.

An electric vehicle, solar panels or a heat pump can make the timing of consumption more important. Compare import, export and equipment-control arrangements separately; fitting a smart meter does not itself guarantee a particular payment or saving.

You can switch supplier with a smart meter. Check whether the new supplier can operate your equipment in smart mode, particularly if there have been past communications issues. The supplier can explain whether an older meter needs further work or replacement.

Installation, data and prepayment

Household installation in the national rollout is normally arranged through the supplier without an upfront installation charge. Installation still has costs within the wider energy system. Ask about the appointment, access requirements and any temporary interruption before agreeing it.

Meter data shows consumption and can reveal patterns. Ask your supplier how data is collected and used, what choices apply and how to exercise them. The government sets out household rights and expectations, including data and support provisions.

Some smart meters can operate in prepayment mode. That capability does not mean a supplier may switch someone to prepayment without following the applicable rules and suitability checks. If payment arrangements are a concern, contact the supplier and seek independent help.

Smart meters for small businesses

Business eligibility, equipment, installation terms and data services can differ from household arrangements. Ask who is responsible for metering, what information will be available, and whether any charges or contract conditions apply.

More detailed data can help a business identify overnight demand or compare opening and closed periods. It does not replace checking contract prices, taxes or the suitability of operational changes.

What to do if something goes wrong

  • Identify whether the issue concerns the display, missing readings, the bill or the physical meter.
  • Keep the dates, error messages and any accessible readings.
  • Contact your supplier and ask what it will do and whether manual readings are needed.
  • Check subsequent bills to confirm that the issue is resolved.
  • Use the supplier’s complaints process if it remains unresolved.

Sources and further reading

Browse the Hub: Household resources · SME resources

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