How do smart meters work? (2024)

A smart meter is a device that replaces an old fashioned standard meter in your home to measure your gas and/or electricity use. But how do smart meters work?

In basic terms, a smart meter does a very similar job to a traditional meter with the added function that it sends meter readings to your energy supplier automatically. This means you can see your energy usage in almost real time on your suppliers app or website, see your exact usage over short periods of time (for example every 30 minutes) and have bills automatically calculated for you every month. You will still have a separate meter for gas and electricity.

If you have an in-home display, you will also be able to see your usage over various periods of time on this without having to visit your suppliers app or website.

What this means for you is that no one needs to manually read your meter to determine how much gas or electricity you have used and you will no longer have a technician from the energy company visit your home to obtain a meter reading periodically.

A bit more detail on how smart meters work

If you have a dual fuel setup (gas and electricity), then you will likely have a communications hub which is part of your electricity smart meter. If your gas smart meter was installed (or this is the only smart meter you have) then you may have a separate communications hub.

Your smart meter works by firstly sending your energy usage to this communications hub and then sending it wirelessly to a DCC (Data and Communications Company). There are two of these companies in the UK, Arqiva Limited covers the north of the country and Telefónica cover the south.

Once the data has reached the DCC, then other companies are able to access it. This includes your energy supplier, the gas and electricity network operators and other authorised third parties.

In term of transmitting data, smart meters don’t need a standard internet connection to work or communicate. They use either a HAN (Home area network) or WAN (wider area network). The HAN network 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?

There are three different ways in which you can read your smart meter.

The easiest way is to look at your IHD, this will let you see your current usage, historic usage and various other data.

If this isn’t working for some reason, then you can physically go to the meter and the electronic display should give you the latest reading of usage.

The third way is to visit your suppliers website or app, this will likely give you the most detailed information and all your historical data with that supplier. It will also show your latest reading the supplier has received, this however may not be as up to date as your IHD or the smart meter display.

Sometimes you may be able to see you usage data on the suppliers app/website even if your IHD isn’t working.

Are smart meters accurate?

Yes, they are generally very accurate. There are strict standards set by the industry they must adhere to and they are strenuously tested before being rolled out.

In fact, they are generally considered more accurate than traditional meters because they don’t rely on mechanical components which can become less accurate over a long period of time.

There have been issues with the accuracy of some people’s meter readings, but these are normally due to either installation errors or problems with the equipment.

In terms of billing, because your smart meter is continuously transmitting your usage information, they are extremely accurate. You will no longer 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 at any time.

Are they real-time?

Smart meters don’t work in real-time, but they are close. They update your gas information every 30 minutes and your electricity usage every 10 seconds.

Do I have to have a smart meter?

Smart meters are not compulsory. If you do not want it, there is no legal requirement to have it installed.

If you have a faulty existing meter that needs to be replaced, it may not be possible for this to be replaced with a traditional meter and you may her to have a smart meter instead.

You will have to have a smart meter to access certain tariffs with some suppliers, for example the Octopus Agile Tariff.

Even though a smart meter is not a legal requirement, it will likely limit your options in terms tariffs you can switch to and may mean you have to pay more for your energy as a result.


Hi, I'm Rob and I run I initially started this project 5 years ago when I was looking to switch energy suppliers and found there wasn't a website that provided simple, data backed reviews on all the suppliers available. Since then, I spent have a lot of time (too much some may say!) looking at all publicly available data about each supplier and writing reviews using this information. These reviews are updated as regularly as possible and any data is backed up by a source where necessary. I have also started writing guides on various energy related topics which hopefully you will find useful. If you find any issues, please use our contact form to let us know.

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