What is a Distribution Network Operator (DNO)?

Which DNO covers my area?

Every business premises in Great Britain is served by one DNO, based entirely on location. You can't choose your DNO the way you choose an energy supplier.

To find out who yours is, check your electricity bill (it's often listed there) or use Ofgem's postcode checker at ofgem.gov.uk.

There are six main DNO groups covering Great Britain, each licensed and regulated by Ofgem:

Your DNO doesn't change when you switch supplier. It stays the same unless you move premises.

What does a DNO letter mean for your business?

Getting a letter from your DNO can feel a bit out of the blue, especially if you've never heard of them before.

Most DNO letters are routine. Common reasons include planned maintenance, notifications about network upgrades, requests for access to equipment on your site, or updates related to an application you've submitted.

In most cases it doesn't mean there's a problem with your supply. That said, if it's asking for a reply or any action on your part, don't ignore it. Delays can hold up works or approvals that affect your premises.

If you're not sure what it means, start by checking the reason for contact and whether there's a deadline attached.

What is a DNO application?

You'd need to make a DNO application any time your business requires a change to its electricity connection.

That might mean increasing your supply capacity, connecting a new building, upgrading an existing connection, or installing onsite generation such as solar panels. These aren't things you can arrange through your energy supplier. They go directly via your DNO.

The process typically works in stages: an initial request, a technical assessment, a formal offer, and then scheduling of the physical work. Timelines vary. A straightforward application can move fairly quickly. Larger upgrades take longer, particularly where significant engineering work is involved.

Knowing what to expect helps you plan projects more realistically and avoid getting caught out by lead times.

What is a DNO certificate?

A DNO certificate is a document confirming specific details about your electricity connection or installation. Businesses encounter a few different types.

Electrical Installation Certificates confirm that installation work has been carried out safely and to the required standard. G98 and G99 certificates relate to embedded generation, such as solar panels or battery storage, and confirm that your system has been approved for connection to the grid. MPAN documentation (Meter Point Administration Number) identifies your specific electricity supply point and is used by suppliers and network operators alike.

Keep these on file. They're often needed when you switch supplier, make changes to your connection, or move into new premises. Missing documentation tends to slow things down at exactly the moment you don't want it to.

How does your DNO affect your business energy costs?

You don't pay your DNO directly, but their costs do show up on your bill.

DNO network charges are passed through by energy suppliers as Distribution Use of System charges, known as DUoS charges. These sit within your unit rate or standing charge, so they're not always visible as a separate line item.

DUoS charges vary by region, voltage level and time of use, which is why two businesses with similar usage can face different network costs depending on where they're located. It's one of the reasons it's worth reviewing your commercial electricity tariff regularly. The network charges are outside your control, but your tariff isn't.

How can businesses get the best deal on their energy tariff?

Your DNO is fixed by location. Your energy supplier and tariff aren't.

We've been helping UK businesses compare and switch energy since 2007, and we've saved customers more than £150 million in that time. We work with a wide range of trusted suppliers, so you can see what's available across the market and make a clear, informed decision.

Compare business energy deals now, or browse our full list of energy suppliers if you'd like to understand your options first.