Smart Meters: The Ultimate Guide

Table of Contents

What is a smart meter?

Smart Meter is a term that we often hear when talking of energy bills and suppliers, but what exactly is it? A smart meter is a device that replaces the need for a standard meter in your home to measure your gas and/or electricity use. The smart meter sends the data collected to your energy supplier automatically. They then use this information to calculate your bill. What this means for you is no one needs to manually read your meter to determine how much gas or electricity you have used or have a technician from the energy company visit your home to obtain a meter reading.

How does a smart meter work?

Smart meters use their technology to send your energy usage information wirelessly to your supplier. It’s then sent to a national framework and from here your supplier can access the information and add it to your account to calculate your bills and update your account information.

How do they communicate/transmit data?

Smart meters don’t need a standard internet connection to communicate. They use either the HAN (Home area network) or WAN (wider area network), the HAN network is what your digital devices in your home use to communicate with each other. Any communications do not happen via the internet. This allows your smart gas and electricity meters to communicate with each other and also with your in-home display where you can visually monitor your usage.

How are smart meters read?

Automatically. Your smart meter collects data on how much energy you are using and sends this continuously to a national framework called the DCC where your supplier can access the information. This takes all the guesswork out of billing and you only receive a bill for the amount of energy you have used.

Are they accurate?

Because the smart meter is continuously transmitting your usage information, they are extremely accurate. No longer will you receive an estimated bill or have to manually read your meter. The smart meter removes all the guesswork and you’ll even be able to determine how much you are spending in pounds and pence on the user display panel.

Are they real-time?

Smart meters are nearly real-time, they update your gas information every 30 minutes and your electricity usage every 10 seconds.

Do I have to have a smart meter? Are they compulsory/mandatory?

Smart meters are not compulsory. If you do not want it, there is no legal requirement to have it installed as yet. There has however been a big government push to get them in households across the country.

Pros and cons of smart meters: Why should I get a smart meter?

Smart meter technology is designed to make life easier and it could also save you money. Once one is installed you’ll also get access to cheaper energy tariffs by switching to a smart meter with your supplier. Let’s look at the pros of having a smart meter installed:

Free of charge

There is no direct charge to have a smart meter installed.

You could save money

Having a smart meter gives you an insight into how much energy you are using and what effect different actions have on your usage and spend. It can help you to modify your behaviour, and by doing so you can trim money off your energy bill. Being able to see your energy cost in pounds and pence rather than in kilowatt-hours helps users translate how using energy translates into spending.

You don’t need to provide meter readings

Because smart meters automatically transfer their data to the energy supplier, you never need to get the torch out and scramble around in a dark cupboard to get your meter reading or have an engineer knock on your door looking for a meter reading again.

You are likely to benefit from better deals

Energy suppliers tend to offer better tariffs to customers who agree to have a smart meter installed. Make sure you check out what deals you could get by using a smart meter.

No more estimated bills

Because of the automatic transfer of your energy consumption, your energy supplier will never have to estimate your bill again, when you don’t have a smart meter and you fail to give your supplier a meter reading, they traditionally base your bill on an estimate of your past usage. In the past, this has resulted in problems for consumers who end up being seriously over or undercharged. With a smart meter, this is no longer a worry.

Can benefit prepaid customers

If you happen to be on a prepaid tariff with your supplier, a prepaid smart meter can help you keep better track of your current balance, some even play an audible sound when you are running low. You can even top up your meter using an app on your smartphone taking away those annoying trips to the newsagent to top up your balance.

Smart meters vs regular meters: are smart meters better than normal meters?

A smart meter monitors your real-time energy usage and continuously sends your meter reading to your supplier. This means your bills are more accurate and you no longer need to give readings manually. With a regular meter, you will need to take a manual meter reading regularly. If you forget to do this or no one is able to gain access to read your meter, then you could face receiving an estimated bill. This is likely to result in either over or underpaying for your energy supply.

What are the benefits of getting a smart meter?

Smart meters take the hassle out of meter readings because they happen automatically. Your bill will always be accurate because it is based on your actual energy usage. It displays your usage in pounds and pence, which allows users who are pro-active to find ways to reduce their energy spend by adapting their behaviour.

Will it save me money?

By itself, a smart meter will not save you money. You need to monitor the information it supplies about your energy usage and adapt your behaviour to reduce your energy bill. It’s an excellent tool for monitoring which actions cost more in energy than others and then consider how you could change things to save money. This could be washing at a lower temperature or reducing your heating by a degree or 2.

Smart meter disadvantages? Are smart meters a con?

Smart meters have many benefits, but what about disadvantages? One of the biggest disadvantages is the cost. Although they are free of charge. The government will need to recoup the cost of the ÂŁ11 billion rollout somewhere. This will be done by adding a levy to energy bills over the next few years.

Smart meters do not automatically save you money. You can save money through proactive use and changing your energy habits based on the information it gives you. Overall, the pros of smart meters certainly outweigh the cons, but the cost and the fact it’s on the user to make money-saving changes should be noted, here we explore some disadvantages of smart meters in more detail:

Cons of smart meters


The roll-out program of smart meters didn’t come cheap. The initial cost was 11 billion, suppliers will need to recoup this through energy bills over the next few years. According to citizen’s advice, the rollout is likely to cost 1 billion more. Which could lead to approximately ÂŁ390 added to every household’s bills spread over the next few years.

You have to be proactive to save money

Unfortunately, the smart meter doesn’t save you money without you having to take any action. To reap the benefits, the householder needs to use it as a tool to monitor times when your energy spend is higher than it needs to be and look at ways to reduce your usage, which in turn will save you money.

They can stop working after switching energy supplier

The first generation of smart meters has a fault which means when you switch energy suppliers they lose their functionality. Newer models being rolled out today are the second generation and do not have this problem, but the rollout so far has been limited.

Smart meters are not available to some prepayment tariff customers

The rollout of smart meters on prepayment tariffs has been limited. They do exist and there are many benefits of having one if you pay by this method. Hopefully, more suppliers will offer smart meters to this group of customers.

Will a smart meter mean I’m more likely to be overcharged?

No. A smart meter will mean your bills are more accurate than ever before as it is continuously sending information on your usage to your supplier. This means so your bill will always be based on your actual use.

Are smart meters free?

Yes, there is no direct charge to supply or install a smart meter. The government’s roll out of smart meters has so far cost 11 billion. Suppliers will recoup this over a number of years by adding a small levy to everyone’s energy bills.

So, should I get a smart meter?

The benefits of getting a smart meter clearly outweigh the disadvantages. No more estimated bills, and no more manual meter readings. You can monitor your energy usage in real-time and adjust your habits to reduce your energy bills. There are many reasons why you should consider getting a smart meter.

How do I get a smart meter?

The government has a target to offer every household in Britain a smart meter by the end of 2025. The first step to request one is to contact your energy supplier for more information about their plans to install smart meters. If your supplier is currently rolling out smart meters they will offer to book an appointment to come and install a meter.

How do I know if I can get a smart meter?

By 2025 the government aims to supply a smart meter to every home. To find out if you can have one now you will need to contact your energy supplier. They should be able to advise if you can have one installed and how long it is likely to take.

Installing a smart meter: How smart meters are installed?

In most cases, your supplier will give you a date for your smart meter installation. An engineer from your energy supplier will come to your home to install the smart meter and you will need to be home while the installation takes place. They will need access to your gas and electricity meters to install your new meters. The engineer will need to turn off the gas and electricity supply for a short period, This is usually less than 20 minutes. After installation, the engineer will test the smart meter to ensure it is working correctly. Once they are happy they will talk you through how it works, and answer any questions you may have.

How long does it take?

In most cases, an installation takes between 1 hour and 90 minutes. This will depend on the location of your existing energy meters and if they are easy to access.

Is installation safe?

Yes. All engineers that fit smart meters have undergone training and hold accreditation to do so. You can always ask to check their ID card for proof of their competence. They will always take the necessary precautions to make sure the smart meter is installed safely. This includes turning off the gas and electricity supply while installing smart meters and making sure everything is working correctly before they leave.

What does a smart meter look like?

A smart meter, on the face of it, doesn’t appear to look much different to a traditional gas or electricity meter. As with traditional meters, they can come in different shapes and sizes. Their differentiating feature is they tend to have a button that you can cycle through several displays when pressed. It is common for people to confuse the in-home display with the smart meter. These also come in different shapes but tend to have a larger display to show your energy spend/usage.

How big is a smart meter?

Smart meters for your gas supply are similar in size to traditional gas meters, a smart electricity meter tends to be slightly larger. If you are wondering if it will fit where your existing meter is, the general guidelines are as follows: Your existing meter should have approximately 30 cm of free space on either side and in front to comfortably install a smart meter. If you are in any doubt, contact your energy supplier before installation.

How to read a smart meter?

How you read the smart meter will depend on which generation of smart meter you have installed, and the variation. Here we look at the most common smart meter set-ups and how to take a reading:

When viewing your gas or electricity meter you need to look out for a number followed by m3 for gas or KWH for electricity. This is your gas or electricity reading and the number you need to make a note of. When taking a reading it is important to ignore the numbers after the decimal place. As an example if the display reads 72.369 your reading should be simply 72.

Next to the display, there will be a way of interacting with the smart meter. The most common setup is a display with a keypad with the numbers 0-9. If this is like your meter you simply need to press 9 to view your reading.

A variation on this is a smart meter that has an A and B button instead. If you have one of these variations, press the A button until you see credit on, then press it again to show the meter index. Press once more to view your reading.

Another type of meter has a left or right arrow. With this version, you just need to cycle through until your meter reading with m3 or KWH shows on the display.

If you have a smart meter with no buttons it will likely cycle through the information by itself. When it does this you need to look out for a reading starting R1 also followed by KWH. By recording these numbers you will have all the information you require to give a reading.

If your meter is different to the ones mentioned above, your supplier will be able to help guide you through the meter reading process.

What information does a smart meter IHD display?

Your smart meter display shows you all the information required to keep an eye on your energy usage and spend. It will display your real-time energy use for electricity and every 30 minutes for gas. It will display how much you have used in the last hour, day and month and exactly what it cost you. You’ll also be able to see at a glance whether your energy use is low, medium or high.

If you are on a prepaid meter, it will also display your remaining credit, how much emergency credit is available and the time it was activated. You’ll also get a notification if your credit is getting low.

Can smart meters be hacked? Are they dangerous?

No, they are highly secure. Smart meters do not use your internet connection, they use their own closed network system to prevent security risks and to prevent hacking. Smart meters have been designed with the assistance of top cybersecurity experts including the government and GCHQ. It’s understandable with smart meters being a relatively new technology that people worry about the safety aspects of the device. All smart meters have undergone rigorous testing to meet EU legislation to ensure they are both stable and secure.

Smart meter problems: What happens if it goes wrong?

Occasionally your smart meter or in-home display may encounter a problem. When this happens one of the most common issues to occur is the smart meter turning dumb when the user switches supplier. This is where the smart meter loses its functionality and is most common with first-generation smart meters. If this happens to you in the short term you will have to supply your meter readings the old-fashioned manual way. To resolve the issue, first-generation smart meters will now connect to the same network as the newer second-generation versions. This is an automatic fix and when it’s done you’ll be able to switch suppliers and retain all the functionality of the smart meter.

Some customers may still receive estimated bills and in most cases, the root cause is that the smart meter is not sending meter readings automatically. The cause of this is the loss of connection to the HAN or WAN networks. To fix this issue you will need to contact your energy supplier. Their technical support team will go through a health check with you to try and get your meter working again or identify the issue.

If the in-home display stops working and is displaying a lost connection or data lost message, the tried and tested method for fixing technology by switching it off and back on again could well resolve the problem. If your IHD has completely frozen, then unplugging it and letting the battery discharge before plugging it back in is likely to resolve the issue.

With any of the above problems, if you are in any doubt about how to resolve any issue with your smart meter set up contact your energy supplier for further advice.

Can smart meters be wrong or give false readings?

For the most part, smart meters are installed and give more accurate bills than manual readings. There have been reports of smart meters either overcharging customers. However, this is the minority rather than on mass. We have to remember that there are 21.5 million smart meters in operation in the UK. As with all technology, from time to time a fault may occur. If you suspect your meter reading is inaccurate, contact your energy supplier. They will most likely ask for a manual reading then follow up with some testing on your smart meter if they find it to be giving false readings.


Can I refuse a smart meter?

Yes. You are under no obligation to have a smart meter if you do not want one.

Do I need to get a new smart meter every time I switch suppliers?

No. You are free to shop around for an alternative energy supplier as you would when using a traditional energy meter.

How do I move suppliers if I have a smart meter?

You can move suppliers as you would have in the past. Either by contacting an energy company directly or using a comparison website or auto-switching service. If you have a newer smart meter your supply and automatic meter reading will continue without interruption. If you have an older smart meter you can still switch in the same way. Your smart meter is likely to temporarily lose some of its functionality after the switch. This is usually a quick fix and you may just have to give one or two manual meter readings in the meantime.

Can I switch tariffs if I have a smart meter?

Yes of course. Switching tariffs with the same or another supplier is easy with a smart meter. Once the switch happens, your smart meter will automatically update to the new tariff information. If you are changing suppliers you may lose some functionality but this is only temporary.

Do smart meters work for both gas and electricity?

Yes, both smart gas and smart electricity meters are part of the smart meter roll out across the UK.

What if I have a prepayment meter?

Some energy suppliers have started rolling out prepayment meters to their customers on these tariffs with more due to follow soon.

Do smart meters work with economy 7?

Yes you can get smart meters that work with economy 7. Once your economy 7 smart meter is set up your rates will show on your smart meter display.

Will smart meters work with solar panels?

Yes, you can have a smart meter that supports solar panels. However, you’ll need to check with your supplier as not all energy companies have set up their smart meters to read the information exported from solar panels.

Smart meters and fit payments

Owners of solar panels and smart meters will still receive their FiT payments as before.

What’s the difference between SMETS1 and SMETS2?

Put simply, the SMETS1 is the first generation of smart meters and SMETS2 is the second generation. Both support accurate, near real time energy readings. The first generation was found to work fine until the user switches the supplier when it temporarily loses functionality, this is because the SMETS1 uses a closed network only the supplier can access. However, the SMETS2 communicates over a data & communications company network which all suppliers have access to. This makes the second generation of smart meters compatible across the industry and as a customer you can switch without losing any of the benefits of the smart meter.

How do I know if my smart meter is smets1 or smets2?

The SMETS2 rollout didn’t start until 2018, so if you know your energy meter is older than this, it’s likely to be of the first generation. Even after 2018, suppliers were still trying to use up the stock of this version. The only way to be sure which generation you have is to ask your energy supplier.

How to put emergency electricity on smart meter

If you have a prepaid meter you’ll have an option to put emergency credit on your smart meter so your electricity supply doesn’t switch off if you are running low on credit. You can activate your emergency credit through the menu system on your smart energy monitor.

What happens if I already have an old smart meter?

There are some older smart meters out there known as non SMETS. These can only be read by the energy supplier that installed them. If you have one of these, it’s likely in the future you will receive an upgrade to a SMETS2 meter. If you have a first-generation SMETS1 your supplier will not replace this as it will continue to function.

Can I have my smart meter removed?

You are under no obligation to have a smart meter installed. If your property already has one that you do not want then you can ask for it to be removed. Your energy supplier could potentially replace it but may levy a charge. In most cases where a customer doesn’t want a smart meter, it can simply be put into dumb mode. This means it functions as a traditional meter and does not send information over the network.

Which smart meters are best?

All smart meters offer similar functionality and identical benefits, so it’s impossible to say that one is better than another. SMETS2 as the second generation is more advanced and has no problems functioning when you switch suppliers like the first generation. But otherwise, there are no clear benefits of one over another.

Can you get a smart meter as a landlord?

If you are a landlord and responsible for paying the energy bills, then yes you can apply for a smart meter at your rental property and for your own property.

Do smart meters work without Wi-Fi?

Yes. Smart meters do not use your Wi-Fi connection. Your smart meter sends information over an isolated and secure network connection.

Can a smart meter be installed outside?

Yes. If your old meters are located outside, the new smart meters will be installed in the same place.

How do I know if I already have a smart meter?

The biggest clue is you won’t have to supply meter readings manually to your energy supplier anymore. If you have an IHD or energy monitor that shows your usage and monthly spend. If you’re still not sure your energy supplier can confirm this.

How much electricity does a smart meter use?

A smart meter uses only 1KWH of energy per year to operate. That will cost you less than ÂŁ1.

Can I buy a smart meter?

Smart meters are supplied free by your energy supplier. However, some clip on smart meters are available to buy online which can be attached to your existing device. It’s recommended that you contact your energy supplier in the first instance to find out their plans to roll out smart meters to your location before making such a purchase.



Rob runs The project initially began when he switched energy suppliers for the first time and found there wasn't a website that provided simple, data backed reviews on all the suppliers available. Since then, Rob has spent considerable time looking at all publicly available data about each supplier and writing reviews using this information. Reviews are updated as regularly as possible and any data is backed up by a source where necessary. If you find any issues, please use our contact form to let us know.

  1. Helpful information

  2. on a smart meter, not a tracker can I read the time-date and see the day and night economy 7 readings

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