Big Business: moving from a one to a three phase meter


If your business uses a lot of energy, then you might need a three phase meter installed, allowing you to access a lot more power from the grid. We are increasingly getting requests for three phase meters, so here is everything you need to know about the installation process.

The difference between a single and a three phase meter:

Typically, all domestic homes and small to medium businesses will have a single phase meter.

With a single phase meter, one alternating current (AC) is supplying your property through one single wire. This is plenty to power a regular business or home, so long as you don’t have a jacuzzi running 24/7 and a whole fleet of electric vehicles charging outside!

Three phase meters are usually only necessary for larger industrial and commercial businesses that use a lot more electricity. A three phase meter has three wires with three alternating currents (AC) supplying the meter and site, so much more power can be used.

We tend to get requests for three phase meters when...

  1. Businesses build a new site with a new grid connection that is going to use a lot of electricity.
  2. Businesses are expanding their current operations or site, so they will begin to use a lot more electricity.
Difference between a one and three phase supply

Things to note about the installation process:

🚨🚨🚨It is important that your distribution network operator (DNO) comes out to attend your site before you have a three phase meter installed. 🚨🚨🚨

Your distribution network operator (DNO) is the company that owns and operates the power lines that connect the national grid to your property. There are 14 distribution networks across the country and a quick google should be able to tell you which network your business is in.

Alternatively, if you are an existing customer you can email us at to confirm your GSP and DNO. If you are still on supply with another energy supplier, they should also be able to confirm this information for you.

Your DNO will check whether your existing wiring is fit for purpose and whether your property is capable of having a three phase meter installed. Your DNO will also be able to instruct on what kind of meter is best for you; whether you need a smart meter or an AMR can be dependent on how much power you use.

You should also let us know once you have agreed a date with your DNO to attend the site.

We can book you an appointment with our lovely meter installation team on the same day as the DNO is coming to visit. Preferably, if your DNO comes in the morning then our team can come later that day to install the meter. This way you won’t be left without power for long and can begin your operations in no time!

Types of three phase meters:

Like single phase meters, three phase meters can come in all different shapes and sizes. You can have both half-hourly and non-half-hourly three phase meters, and the most common three phase meters in the market right now are AMR meters.

Last year, the first ever SMETS 2 three phase meters were introduced. We are now rolling smart meters out to our customers, so register your interest if you would like to get one fitted!

One thing to note is that the existing three phase SMETS 2 meters available on the market can reach power outputs of 300 amps (100 amps per phase). If you require more power than this, you'll need to get an AMR meter installed. Your DNO can advise you on what the power level and right meter will be for your business.

If you have any more queries about three phase meters, you can get in contact with our metering boffins by emailing


Published on 30th March 2021 by:

image of Eloise Moench

Eloise Moench

Copywriter & marketing executive

Hey I'm Constantine, welcome to Octopus Energy!