Smart meters explained: how they work and whether to get one | So Energy

A smart meter is a gas or electricity meter that sends your readings to your supplier automatically. It replaces your traditional meter, so your bills are based on the energy you actually use, not estimates. It comes with an In-Home Display, a small screen showing what you're using and what it costs.This guide covers how smart meters work, their pros and cons, common myths, costs, and whether you can get one. Ready now? Book a free smart meter installation.

What is a smart meter?

A smart meter is a gas or electricity meter that sends your readings to your supplier automatically. It replaces your traditional meter, so your bills are based on the energy you actually use, not estimates. It comes with an In-Home Display, a small screen showing what you're using and what it costs.

It measures how much gas or electricity your home uses, like any meter. The difference is what happens to the reading next.

A traditional meter keeps the reading on the meter, so the customer has to read it and send it themselves. A smart meter sends readings to your supplier by itself.

There are two separate pieces of kit:

• The smart meter replaces your old meter, usually in the same spot. It measures your energy use and sends the readings.
• The In-Home Display is a small, portable screen. It shows your energy use and costs, but doesn't send anything to your supplier.

You can have a smart meter for electricity, gas, or both. If you have both, they share one communications hub. This is the small unit that does the sending.

By the end of June 2026, Great Britain had more than 42 million smart and advanced meters. That's 72% of all meters, according to Government figures.

How do smart meters work?

Here's the journey a reading takes, from your meter to your bill.

1. The meter measures your energy use. Electricity is measured in kilowatt hours, or kWh, the unit you're charged in. Gas is measured by volume, then converted into kWh on your bill.
2. The communications hub sends the reading. It uses a secure national network run by the Data Communications Company (DCC). This network was built only for smart meters. It doesn't use your broadband or Wi-Fi.
3. Your supplier receives it. Readings are encrypted, and only your supplier gets them, plus anyone you've given permission to.

Your meter records your energy use every half hour. How often your supplier collects those readings depends on your settings. It can be monthly, daily or half-hourly. With So Energy, you can choose half-hourly readings in your online account.

Your meter and In-Home Display also talk to each other. They use a short-range wireless link inside your home.

What the In-Home Display shows you

Your In-Home Display shows:

• how much energy you're using right now
• what you've used and spent today, this week, this month and this year
• your credit balance, if you pay as you go

Electricity figures update every few seconds. Gas figures update about every 30 minutes. Gas meters run on batteries, so they send data less often.

It won't show you what each appliance uses. But you can work it out. Switch the kettle on, and watch the figure jump.

Does it need to stay plugged in? Yes, to keep the screen on. But unplugging it doesn't affect your meter, and your readings still reach us. Plug it back in and it reconnects.

How often are readings sent, and who decides? You do, within rules set by the Government. You can change your settings in your So Energy account.

Why doesn't it match my bill? Your In-Home Display is a guide, not a bill. If your tariff has changed, it might still show the old price. Your bill is always based on your meter readings and current rates. If the gap looks big, let us know.

If your display has stopped working, try our In-Home Display troubleshooting page.

SMETS1 and SMETS2 meters

There are two generations of smart meter, named after the Smart Metering Equipment Technical Specifications (SMETS).

To find out which you have, ask us. Some meters also have SMETS1 or SMETS2 on a label. A meter fitted before 2018 is likely to be first generation.

We cover what happens when a SMETS1 meter loses its smart features in the drawbacks section.

What a smart meter looks like and how to read it

A smart electricity meter is a box with a digital screen and a small keypad. The buttons are usually marked A and B, or numbered. The communications hub is a smaller unit fitted on top of or next to it.

A smart gas meter sits on your gas pipe and has a similar screen and buttons. It sends its readings through the hub on your electricity meter.

A traditional meter usually has rolling numbers or dials. Some have a digital screen, but no communications hub.

You probably have a smart meter if you have an In-Home Display and we never ask you for readings.

Reading your smart meter

Most of the time, you won't need to. But you might if:

• your meter isn't working in smart mode
• there's a network problem and we ask you for a reading
• you're moving home
• a reading looks wrong

On most smart electricity meters, press a button to wake the screen. Keep pressing to scroll until you see the import reading, shown in kWh.

The benefits of a smart meter

Accurate bills and no more manual readings

No one likes sending meter readings. A smart meter does it for you, so you never have to send one again.

Your readings go straight to your supplier, so there's no need for estimates. You're billed for the energy you actually use.

That matters if you've ever had a run of estimated bills, then a big catch-up bill. With accurate readings, your balance keeps up as you go.

Seeing what your energy actually costs

Seeing your energy use in pounds and pence makes it easier to make choices that fit your budget. You might notice:

• what your home uses overnight, when everyone's asleep
• how much more the tumble dryer costs than air-drying your washing
• whether the heating comes on when nobody's home

For more detail, switch on half-hourly readings in your account. Our guide on what uses the most electricity in a home shows where the biggest savings usually are.

Access to time-of-use tariffs

A time-of-use tariff charges different prices at different times of day. Energy is usually cheaper overnight and pricier in the early evening.

You need a smart meter to get one. We need to know when you used energy, not only how much, to bill you correctly.

Here's an example with our So EV tariff, which gives you 7.5p per kWh from midnight to 5am. Say your standard rate is 25p per kWh, and you charge your electric car with 40kWh overnight:

• on the overnight rate, it costs £3
• on the standard rate, it would cost £10
• charge twice a week, and you'd save around £728 a year

You can run the dishwasher or washing machine on a timer in the same hours.

There’s a bigger change happening too. Right now, suppliers buy electricity in advance, based on estimates of how much their customers will use and when. Marketwide Half-Hourly Settlement (MHHS) is changing that. Suppliers can now use real half-hourly readings from smart meters, so they can plan more accurately. Over time, that makes it easier to offer cheaper rates when demand is low.

Learn more about half-hourly settlement

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Getting ready for solar, an EV or a heat pump

Planning solar panels, an electric car or a heat pump? A smart meter does a lot of the groundwork.

Solar panels

With solar, electricity can flow both ways. You import from the energy grid when your panels aren't producing enough, and you can export to the grid when they produce more than you need.

A smart meter measures both separately, every half hour. That matters for two reasons:

• You get paid for what you export. The Smart Export Guarantee pays you for electricity you send to the energy grid. Your supplier needs real export readings to pay you accurately.
• You can see what your panels save. Your import drops on sunny days. That helps you plan when to run appliances, so you use more of your own electricity.

Add a solar battery, and a smart meter lets you pair it with a time-of-use tariff. Charge the battery when grid electricity is cheapest, then use it at peak times. Find out more about solar panels.

Electric cars

EV tariffs like So EV need a smart meter set to half-hourly readings. That's how we bill your overnight charging at the lower rate. Without one, you pay the same rate whenever you charge. Explore our EV chargers.

Heat pumps

A heat pump runs on electricity, so your electricity use goes up when you switch from gas. A smart meter helps you track what it costs.

The drawbacks to weigh up

Smart meters work well for most homes, but not all of them. Here's an honest look at the downsides.

Connectivity, older homes and flats

A smart meter needs a signal to send readings. Where signal is weak, it may store readings and send them later. In some places, the signal isn't strong enough for it to work at all.

Some homes are harder to fit:

• Flats. Meters are often in a basement or shared cupboard. The In-Home Display may not connect from that far away.
• Thick walls or metal meter cabinets. These can block the signal.
• Older wiring. Some older electrical systems need work before a smart meter can be fitted safely.
• Three-phase supply. Some larger homes have this. We're unlikely to be able to fit a smart meter for these homes at the moment.

If we can't fit one in your home yet, we'll tell you. You'll keep your current meter and send readings as normal. The technology is improving, so we can look again in future.

When a first-generation meter loses its smart features

People call this a meter "going dumb". The meter stops sending readings and works like a traditional meter, so you need to send readings again.

It happened mostly with SMETS1 meters. They used each energy supplier's own system. If you switched to a supplier that couldn't connect to it, the smart features stopped.

The fix was to move SMETS1 meters onto the national DCC network, so any supplier can use them. The DCC says the vast majority of eligible SMETS1 meters have now moved, but where that wasn't possible, the meter may need replacing.

It isn't solved everywhere yet, so if your meter has stopped sending readings, keep sending them yourself so your bills stay accurate. Then get in touch, and we'll tell you what's happening with your meter

Accuracy, errors, and what a smart meter will not do on its own

Are smart meters accurate? Yes. They must meet the same legal accuracy standards as traditional meters. The Office for Product Safety and Standards approves them before they're used.

Can things go wrong? Sometimes. Readings can arrive late or have gaps. Your In-Home Display might stop updating for a while. Most issues are temporary, and your meter keeps recording your use.

If a reading looks wrong, compare the number on the meter with your bill. Send us a photo of the meter screen, and we'll look into it.

Will it cut my energy use? Not on its own. A smart meter measures and reports. It's what you do with the information that makes the difference – like making small changes in your energy use.

Smart meter myths, and what is actually true

You may have read some worrying things about smart meters. Here are straight answers, with sources you can check.

Your data, and who can see it

What does a smart meter collect? Your energy use readings. It doesn't store your name, address or bank details. It has no camera or microphone, and it can't tell which appliance you're using.

Who can see it? Your supplier, and anyone else you give permission to, like a comparison app. Readings are encrypted and sent over the DCC's secure network.

Do you have a say in how detailed it is? Yes. The Government's Data Access and Privacy Framework sets rules all suppliers must follow:

• your supplier can use monthly readings to bill you
• it can collect daily readings, but you can opt out
• it needs your permission to use half-hourly readings for things like personalised insights or marketing

Half-hourly electricity readings are also used for half-hourly settlement. This isn't part of your bill. The energy industry uses anonymous half-hourly readings to work out what each supplier owes for the electricity its customers use.

Could your data reveal anything about you? Detailed readings can show patterns, like when you tend to be home. That's why the most detailed data needs your consent. You can change your settings at any time.

Just bear in mind, a smart meter holds far less data about you than your phone does.

Radiation and health concerns

Smart meters use radio waves to send readings, like phones and Wi-Fi routers do. It's a fair thing to ask about.

The UK Health Security Agency, the Government's independent health adviser, has looked into it. It found exposure from smart meters is well below international safety guidelines. It's also likely to be much lower than from mobile phones or Wi-Fi.

That's because a smart meter only sends signals in short bursts, between 0.1% and 1% of the time. And it's usually on a wall, away from where you sit. Research published by Public Health England found exposure around a million times below the guideline limit.

Compare that with a mobile phone held against your head during a call. The UK Health Security Agency says radio waves aren't a reason to decline a smart meter.

Whether you have to have one, and whether it ties you to one supplier

Do you have to have one? No. Suppliers have to offer smart meters, but you can choose whether to say yes. Find out more in is a smart meter compulsory.

Will it tie you to one supplier? No. You can switch supplier as normal. A SMETS2 meter, or a SMETS1 meter on the DCC network, stays smart when you switch. Read about switching suppliers with a smart meter.

Do smart meters save money?

A smart meter won’t lower your bills on its own. The savings come from what you do with the information it gives you.

Here’s how it can help:

• See what you’re using. It shows how much energy you use, when, and what it costs, so you can spot where to cut back.
• Pay less by changing when you use energy. It lets you switch to a time-of-use tariff, where the price changes depending on the time of day. Use more when it’s cheaper and you’ll pay less.
• Earn from your solar panels. If you have solar panels, you can sell the energy you don’t use back to the grid through the Smart Export Guarantee (SEG).
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Each of these needs you to make a change. Your meter gives you the information and the options. The savings come from what you do next.

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How much does a smart meter cost?

There's no charge to get a smart meter. You don't pay for the meter, the installation or the In-Home Display. And there's no extra charge on your bill for having one.

So who pays? The cost of buying, fitting and looking after meters is shared across all customers, through everyone's energy bills. That's true whether you have a smart meter or not. Ofgem confirms you pay for your meter and its upkeep through your bills.

Is there a catch? Your supplier shouldn't ask you to pay to have one fitted. If anyone asks for payment to fit a smart meter, don't pay, and contact your supplier directly.

Can you get a smart meter?

Most homes can. You can get one for electricity, gas, or both, including if you only get one fuel from us.

To fit a smart meter, we need:

• good mobile signal where your meter is
• a single-phase electricity supply, which most homes have
• safe access to your meters

If signal or your meter's location is a problem, see connectivity, older homes and flats. If you can't get one right now, you'll keep your current meter and send readings as normal.

What the appointment involves

An engineer swaps your old meters for smart ones. They'll turn off your electricity and gas for about 30 minutes each. Then they'll check everything's working, set up your In-Home Display and take your old meters away.

Check your eligibility and book a free smart meter installation online.

If you rent

It depends on who pays the energy bills.

• If you pay the bills, you can choose to get a smart meter. You don't need your landlord's permission, but it's a good idea to tell them. Check your tenancy agreement too.
• If your landlord pays the bills, it's their decision. Talk to them if you'd like one.

If you're on a prepayment meter

A smart meter can work in Pay As You Go mode, and it makes topping up easier.

• Top up from home. Top up online, in an app or by phone, as well as at a Paypoint.
• See your credit. Your In-Home Display shows how much credit you have left.
• Get a warning. Your display tells you when your credit is running low.
• Change how you pay without a new meter. A smart meter can switch between Pay As You Go and paying after you use energy.

If you top up online, keep your top-up card or key safe in case the app isn't working.

Worried about paying for your energy? We're here to help. Find out about the support we offer.

Smart meters with So Energy

When you get a smart meter with So Energy, you get:

• free installation by a qualified engineer
• a free In-Home Display
• automatic readings and accurate bills, with no estimates
• the option of half-hourly readings, for more detail on your energy use
• access to our time-of-use tariff, So EV

Check if your home's eligible and book your free installation online.

Already have a smart meter? See if a time-of-use tariff suits how you use energy.

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Smart meter Frequently Asked Questions (FAQs)

Do smart meters work with solar panels?

Yes. A smart meter records the electricity you import from the energy grid and export back to it. It records each one separately, every half hour. This means your supplier can pay you accurately through the Smart Export Guarantee. You can also see how much less you import on sunny days. That helps you plan when to run appliances.

Do smart meters need Wi-Fi?

No. Smart meters don't use your home Wi-Fi or broadband. They send readings over a separate, secure national network run by the Data Communications Company. Your meter and In-Home Display connect through their own short-range wireless link inside your home. You don't need an internet connection to have a smart meter.

Can I switch supplier if I have a smart meter?

Yes. You can switch supplier as normal with a smart meter. SMETS2 meters keep working in smart mode with any supplier. Most SMETS1 meters have now moved to the national network, so they stay smart too. If an older meter stops sending readings after a switch, it works as a traditional meter. You can send readings yourself.

What happens if my smart meter stops working?

Contact your supplier. They're responsible for fixing it, and suppliers now have a maximum of 90 days to repair a faulty smart meter. In the meantime, your meter usually keeps recording your energy use. If it stops sending readings, send them yourself so your bills stay accurate. If you think there's a safety issue, contact your supplier straight away.

Do smart meters include a standing charge?

A standing charge isn't caused by having a smart meter. It's part of your energy tariff, and you pay it with a smart meter or a traditional one. It covers the fixed costs of supplying energy to your home, like maintaining the energy grid. Your In-Home Display may show it, but a smart meter doesn't add to it.

Related reading

• Is a smart meter compulsory?
• Switching suppliers when you've got a smart meter
• Time-of-use tariffs and So Unique
• What uses the most electricity in a home?

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Footnote

1. https://assets.publishing.service.gov.uk/media/692587072945773cf12dcfea/Q3_2025_Smart_Meter_Stats_Report.pdf