What Does DNO Stand For? Find Your Network Operator

DNO stands for distribution network operator

A DNO is the company that owns and runs the local electricity wires between the national transmission grid and your meter. Your supplier sells you the units and sends the bill; the DNO keeps the poles, cables, substations and transformers that carry the power to your site, restores supply after a fault, and approves any new or larger connection.

You cannot choose your DNO. It is set by where your site is. Great Britain is split into 14 licensed distribution areas, run by six DNO groups. Northern Ireland is separate and is served by NIE Networks.

For a business thinking about a battery, the DNO matters in three practical ways, covered below: it sets the DUoS charges that a battery can reduce, it approves any battery that can export, and it decides what a connection upgrade would cost.

The 14 areas and six groups

Every Great Britain electricity meter carries a distributor ID, the first two digits of the core MPAN (explained in the next section). The ID tells you the area and so the DNO group.

Some commercial sites are not on a DNO’s network at all. A newer industrial estate or business park can be connected to an independent network operator (an IDNO), which owns the local wires inside the development. An IDNO has its own distributor ID outside the 10 to 23 range. If your ID is not in the table, check which operator it belongs to and ask that operator for its charging statement.

How to find your DNO in a minute

1. Read your MPAN. The MPAN is the supply number on your electricity bill. On a bill it is often printed as a two-line block; the longer number on the bottom line is the core MPAN, and its first two digits are the distributor ID. Match them to the table.
2. Use the Energy Networks Association’s free postcode checker. The ENA publishes a “find my network operator” lookup that returns the operator for a postcode. Use it as a cross-check, and note that it returns a single operator for the postcode, so check the MPAN for a site on an independent network.
3. Ask your supplier or energy broker. The supplier holds the MPAN and distributor ID for every meter it serves.
4. In a power cut, call 105. This free number puts you through to your own DNO for supply faults. It is for emergencies, not for connection questions.

A site with several meters can have several MPANs. Multi-site businesses often find that their branches sit in different DNO areas, so a battery that pays back at one site may not at another.

Why your DNO matters before you buy a battery

1. It sets the charges a battery is meant to cut

Each DNO publishes its own annual use-of-system charging statement. The rates differ by area, and they differ by time band: the red band, in the early evening, is the expensive one for half-hourly customers. A battery that discharges in the red band avoids those charges, which is the saving explained in how peak shaving cuts red-band DUoS. The size of the saving depends on your area’s published rates and on your own half-hourly data, so ask your supplier which charge band and tariff code your meter is on before you trust any payback figure.

Capacity charges also come from the DNO. If your bill carries a charge for authorised supply capacity, the question is whether a battery lets you contract a lower kVA figure, covered in can a battery reduce your kVA capacity charge.

2. It approves any battery that can export

A battery that can push power back to the grid has to be notified to, or approved by, your DNO before it is connected. The route depends on the size of the system, and your installer or the DNO’s own guidance will tell you which applies. The process is covered on our G99 application page. Allow time for it: approval timelines vary by DNO and by how busy the local network is.

3. It decides the cost of a bigger connection

If a new load, such as EV chargers or a heat pump, would take your site past its agreed import capacity, the DNO quotes for the reinforcement. That quote, and how long the works take, can make the project unviable. Some businesses use a battery to stay inside the existing connection instead, as set out in using battery storage to beat a grid-connection constraint. Ask the DNO for its quote before you decide, so you are comparing a real figure against the cost of storage.

What to do next

• Note the distributor ID from each MPAN and write down the DNO for each site.
• Download that DNO’s latest charging statement, or ask your supplier which charges apply to your meter.
• Pull a year of half-hourly data, which your supplier can provide, before you size anything. The peak shaving guide explains what to look for in it.
• Compare what you find with the cost ranges on our cost page.

If you want an independent view on whether storage suits a site, you can send the details through our quote form. We reply by email.