Am I on an IDNO? The distributor-ID checker
Your network is named by the first two digits of the long supply number on your bill (the MPAN, in the box marked with a large S). Type those two digits below. Codes 10 to 23 are the six regional DNOs; 24 and above are Independent DNOs. The full list is in the table further down.
For example 12 (a DNO) or 26 (an IDNO). The result updates as you type. Nothing you type leaves your browser.
This is an Independent DNO: a last-mile network, most often on a new development. Your distribution charges are still capped to the host regional DNO\'s level, and in a power cut you dial 105.
This is one of the six regional Distribution Network Operators. In a power cut, dial 105.
That code is not a current distributor ID.
Distributor IDs run from 10 upward. Double-check the two digits at the very start of the supply number in the box marked S. The full list of valid codes is in the table below.
Source: the industry MPAS distributor-ID list (Energy Networks Association). Codes 10 to 23 are the regional DNOs; 24 and above are licensed IDNOs. New IDNO codes are added over time, so Ofgem's register is the live source.
The short answer
An IDNO (Independent Distribution Network Operator) owns the local "last-mile" electricity network on a development, most often a new-build estate, embedded inside one of the six regional DNO areas. It is fully Ofgem-licensed, you cannot choose or switch it, and Ofgem's Relative Price Control means your distribution charges are no higher than if you were on the regional DNO. You spot an IDNO from a distributor ID of 24 or above on your bill, and in a power cut you still call 105.
Current figures: last updated 2026-06-25
The number of IDNOs grows as new ones are licensed (E.ON UK Network Assets was licensed in 2025). The distributor-ID method, the Relative Price Control and the 105 line are stable. Confirm the live operator list via Ofgem.
What an Independent DNO actually is
Great Britain is divided into 14 distribution licence areas run by six regional Distribution Network Operators (DNOs). They own the established cables under almost every older street. An IDNO is different in one key way: it has no fixed geographic patch. Instead it builds, owns and operates discrete local networks, dropped inside a regional DNO's territory and plugged into it, most often the wiring for a new estate, apartment block or business park.
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1
A development needs a network
When houses or commercial units are built, someone has to design and lay the cables and substations and connect them to the grid. Ofgem opened this work to competition, so a developer no longer has to use the incumbent regional DNO.
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2
An IDNO builds and adopts it
An IDNO (or a contractor working with one) builds the network and the IDNO adopts it: it owns and maintains the last-mile wires for the long term. It funds part of the connection cost in exchange for the regulated income from owning the network.
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3
You move in, on the same rules
Your home sits on the IDNO's network, connected upstream to the regional DNO. The IDNO holds the same Ofgem distribution licence, with the same obligations: 24/7 emergencies, the Priority Services Register, and the price control that caps what you pay.
| Feature | Regional DNO | Independent DNO (IDNO) |
|---|---|---|
| Area covered | A fixed region (one of 14 licence areas) | No fixed area; individual networks anywhere in GB |
| Typical network | Established streets and towns | New-build estates, blocks and business parks |
| Distributor ID | 10 to 23 | 24 and above |
| Licence and regulator | Ofgem distribution licence | The same Ofgem distribution licence |
| Power-cut line | 105 | 105 |
| Can you switch it? | No | No |
The belief that worries new-build buyers: "a private network means I'll pay more"
It sounds plausible. A smaller, independent, profit-making company owns your cables instead of the big regional network, so surely it charges more, or cuts corners on safety. Both halves of that fear are wrong, and the reason is regulation, not goodwill.
The worry
"An independent company owns the wires, so it can charge what it likes and may not answer in an emergency."
What's really going on
An IDNO holds the same Ofgem licence as a regional DNO. Its charges are capped to the DNO-equivalent by the Relative Price Control, and it must provide 24/7 fault cover. You are on the same 105 line and the same Priority Services Register.
Why most explanations get this wrong
Most articles on IDNOs are written for property developers, not residents. They focus on connection costs, asset value and adoption deals, the things a housebuilder weighs up, and barely mention what it means for the person who eventually lives there. So a homeowner who notices an unfamiliar network name finds pages of jargon about the connections market and none of the reassurance that actually answers their question.
There is a second, subtler error: treating "IDNO" as a warning label. It is not. It is simply who happens to own a newer stretch of wire. The practical facts for a resident, capped charges, the same emergency cover, the same inability to switch, are identical to being on a regional DNO.
Do you pay more on an IDNO? The Relative Price Control
This is the question that matters on a bill, and the answer is set by a specific Ofgem rule. The distribution part of your electricity charge (the "DUoS", or Use of System charge) is paid by your supplier to the network and passed through to you. On an IDNO network, Ofgem requires that charge to be held at, or below, the regional DNO equivalent.
Under the Relative Price Control, the distribution charge on an IDNO network is split into two parts, and the two together cannot exceed what a comparable DNO-only customer pays:
A discounted payment to the host DNO
for using the upstream regional network that the IDNO connects into.
A smaller payment to the IDNO
for the last-mile network it owns and maintains on your development.
Add the two together and the total is capped at the DNO-equivalent. So an end customer pays the same distribution charge whether their cables belong to a regional DNO or an IDNO. Being on an IDNO does not raise the network part of your bill.
As with any network, you cannot shop this charge away, it is a regulated cost, not a competitive price. The part of your bill you can change is the supplier and tariff. Whether you are on a DNO or an IDNO makes no difference to your freedom to switch supplier, and no difference to the network charge you are switching around.
Power cut on an IDNO network: who to call
This is the one moment where people worry an IDNO might leave them stranded. It does not. The emergency arrangements are built into the licence.
Dial 105
Free and 24/7 across England, Scotland and Wales. It routes you to your local network operator, IDNO networks included.
24/7 cover is required
IDNOs must provide round-the-clock fault management as a licence condition. In practice many contract their emergency response to the host regional DNO.
999 if there is danger
For a downed or sparking cable, or any risk to life, call 999 first. Then report the fault on 105 or your IDNO's own emergency line.
If your move-in paperwork lists a dedicated IDNO emergency number, keep it to hand, it reaches the team responsible for your network. But you never need to memorise it: 105 works regardless, the same as for everyone else.
Every IDNO distributor ID at a glance
The reference list of Independent DNO distributor IDs. If the first two digits of your supply number are 24 or above, you are on one of these. New codes are added as Ofgem licenses new operators, so treat Ofgem's register as the live source.
| Distributor ID | Independent DNO |
|---|---|
| 24 | Independent Power Networks |
| 25 | ESP Electricity |
| 26 | Last Mile Electricity |
| 27 | The Electricity Network Company |
| 28 | UK Power Networks (IDNO) |
| 29 | Harlaxton Energy Networks |
| 30 | Leep Electricity Networks |
| 31 | UK Power Distribution |
| 32 | Energy Assets Networks |
| 33 | Eclipse Power Networks |
| 34 | Murphy Power Distribution |
| 35 | Fulcrum Electricity Assets |
| 36 | Vattenfall Network |
| 37 | Forbury Assets |
| 38 | Indigo Power |
| 39 | Squire Energy Metering |
| 40 | Utility Assets |
| 42 | Advanced Electricity Networks |
| 43 | IDCS |
| 45 | Aurora Utilities |
| 46 | Aidien |
| 47 | Vital Energi Power Networks |
| 48 | E.ON UK Network Assets |
| 51 | AGR Networks |
Source: the industry MPAS distributor-ID list. To identify your regional DNO instead (codes 10 to 23), use the who is my DNO finder.
What to do with this, in order
Check your distributor ID once
Read the first two digits of your supply number, or use the checker above. 24 or above means you are on an IDNO; it is useful to know, but it changes nothing you need to act on.
Save 105 as your power-cut number
It works on IDNO networks too. If your paperwork lists a dedicated IDNO emergency line, keep that as well, but 105 is enough.
Register if anyone is vulnerable
Join the Priority Services Register if someone in the home depends on power for medical needs. IDNOs run it just like the regional DNOs.
Switch where it actually pays: the supplier
Your network charge is capped and fixed whether you are on a DNO or an IDNO. The supplier and tariff are the part you control, so put your effort there.
The one thing to remember
An IDNO is just who owns the newer wires on your development. It is licensed like a regional DNO, capped to the same charges by Ofgem's Relative Price Control, bound to the same 24/7 emergency duties, and reached on the same 105 line. The only practical difference is the distributor ID on your bill: 24 or above instead of 10 to 23.
As new homes and estates keep being built, more people will find themselves on an IDNO without ever choosing one. It is nothing to worry about, and nothing to act on, beyond knowing that the part of your bill you can actually move is, as always, the supplier and the tariff.
Independent DNOs: frequently asked questions
An IDNO is a company that owns and operates a local electricity distribution network, usually the "last-mile" wires, substations and connections built for a new housing or commercial development. The network is embedded inside one of the six regional DNO areas and connected to it. IDNOs hold the same type of Ofgem distribution licence as the regional DNOs and must meet the same standards, including 24/7 emergency cover.
Read the first two digits of the long supply number (the "MPAN", in the box marked with a large S) on your electricity bill. 10 to 23 means one of the six regional DNOs. 24 or higher means an IDNO. New-build homes and recently developed estates are the most likely to be on an IDNO. You can also check the checker on this page.
No. Ofgem applies a Relative Price Control that caps an IDNO's distribution charges so they are no higher than what an equivalent property would pay if it were connected directly to the host regional DNO. The distribution charge a supplier pays is split between a discounted payment to the host DNO for the upstream network and a smaller payment to the IDNO for the last mile, and the combined total cannot exceed the DNO-only equivalent.
Dial 105, free and 24/7, the same as anyone else in England, Scotland or Wales. It routes you to your local network operator. IDNOs are required to provide round-the-clock fault management, and in practice many contract their emergency response to the host regional DNO. If there is a downed cable or danger to life, call 999 first.
No. As with a regional DNO, the network that owns your cables is fixed, you cannot switch it. On a new development the IDNO is chosen by the housebuilder or developer through the competitive connections market, before you move in. You can still freely switch the supplier that bills you at any time; that is unaffected by who owns the wires.
Ofgem opened the market for new electricity connections to competition. IDNOs compete with the regional DNOs to design, build and adopt the networks on new developments, which can give housebuilders a faster and often cheaper connection. The IDNO funds part of the work in exchange for owning the network and earning the long-term, regulated income from it. The end customer is protected by the same licence conditions and the Relative Price Control.