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Independent Distribution Network Operators (IDNOs): Extending the grid and powering new developments
Independent Distribution Network Operators (IDNOs) are companies that build and operate local “last-mile” electricity networks that extend the existing grid to connect new developments.
Created by Ofgem to introduce competition, IDNOs offer developers faster, more flexible and often lower-cost alternatives to the traditional network operators.
This guide explains the role of IDNOs. Here’s what we cover:
- What is an IDNO?
- The difference between DNOs and IDNOs
- How IDNOs work
- List of IDNOs in the UK
- How do IDNOs affect electricity prices
What is an IDNO?
An Independent Distribution Network Operator (IDNO) is a licensed company that owns and operates electricity distribution networks in the UK.
IDNO networks are typically small, privately owned extensions to the regional grid that connect newly built homes and businesses.
IDNO infrastructure
An IDNO provides the final stretch of network infrastructure that extends the regional DNO’s network to individual properties on a new development.
Here’s the infrastructure that is typically owned and operated by the IDNO:
- Incoming high-voltage supply – An 11kV or 33kV supply cable from the regional electricity distribution network terminates at an IDNO substation.
- IDNO substation(s) – The incoming voltage is stepped down by transformers at substations on the IDNO network to 400V.
- Low-voltage mains cables – Underground cables from the IDNO substations provide a single-phase 230V or three-phase 400V supply to individual properties.
- Electricity meters – The IDNO’s connection terminates at the electricity meter of individual properties on their network.
💡 Electricity meters on independent networks are operated by individual domestic and business energy suppliers, not the IDNO.
End-users of IDNO networks
IDNOs are typically constructed to provide an extension to the grid to support the following types of new development:
- New residential developments – Housing estates, apartment blocks, student accommodation, etc.
- Business parks/logistics hubs – Large-scale commercial sites.
- Data centres – Projects requiring high-capacity networks to support large business energy consumption and demand-side response.
- EV charging infrastructure – Typically constructed alongside new residential and business developments.
- Small-scale renewable generation – Commercial solar panels, commercial solar batteries and small wind farms.
The difference between DNOs and IDNOs
DNOs and IDNOs both operate electricity distribution networks, but they occupy different positions within the energy system.
To understand the distinction, here is a straightforward summary of how electricity flows from generation to end users in Britain:
- Large-scale generators – Gas power stations, nuclear power stations, etc, provide a power supply to the nationwide high-voltage transmission network.
- High-voltage transmission network – The nationwide backbone of the electricity grid (referred to as the national grid) delivers electricity to regional distribution networks.
- Regional distribution networks – The British mainland is divided into 14 lower-voltage regional distribution networks, managed by individual distribution network operators.
- Independent distribution networks – Small local networks attached to DNO networks that distribute power locally to specific new developments.
Individual homes and small businesses can be connected to either an IDNO or a DNO network.
The roles of IDNOs and DNOs are very similar, but the key difference is the scale of the network they operate. A DNO is responsible for thousands of kilometres of electrical infrastructure across an entire region, for example, Northern Powergrid’s Yorkshire-wide network.
In contrast, an IDNO network may serve just a single new development or a cluster of new sites. Due to its smaller scale, an IDNO network typically receives its power from an individual DNO rather than from the high-voltage transmission network.
How IDNOs work
IDNOs typically own and operate the local electricity distribution networks they have built or adopted.
The following section outlines the main responsibilities involved in managing these local networks.
Maintenance, fault response and emergency duties
IDNOs are responsible for all maintenance functions on their networks, including routine activities such as inspecting substations and reactive maintenance when problems arise.
IDNO networks must meet the same engineering and safety standards as those operated by DNOs.
IDNOs are required to have systems and staff in place to provide a 24/7 fault management and emergency response function that is able to respond to power cuts and other issues on their networks.
In practice, many IDNOs contract out these functions to their host DNO.
Connection services
IDNOs must allow anyone to connect to their network, even if the independent network was originally built for individual development.
The IDNO must provide connection quotations in a timely and transparent manner for any new connection requests from individual homes or business properties seeking to be built in the area.
They must also allow Independent Connection Providers (ICPs) to build substations and new connections that extend their network.
The IDNO registers MPANs for new domestic or business electricity connections on its network.
Providing services to energy suppliers
IDNOs do not directly provide electricity tariffs to customers on their networks. Only Ofgem-licensed energy suppliers are permitted to provide this service in the retail electricity market.
Domestic and business energy suppliers pay IDNOs for every kWh of power delivered on their networks, in return for providing the last-mile connection.
To facilitate energy suppliers using their networks, IDNOs are responsible for maintaining the register of MPANs with the market operator Elexon.
List of IDNOs in the UK
The table below lists all licensed IDNOs in the UK, including their distributor ID, and the types of networks they operate.
| IDNO | Distributor ID | Typical electricity networks |
|---|---|---|
| Advanced Electricity Networks Ltd | 42 | Network adoption for residential, commercial and industrial developments across the UK. |
| AGR Networks Ltd | Newly appointed ID pending | A very new IDNO, not yet sector-specific; general GB customers via new networks. |
| Aidien Ltd | Newly appointed ID pending | Adoption and operation of new electricity networks built by developers/ICPs, nationwide. |
| Aurora Utilities Ltd | 45 | Five core sectors: EV charging infrastructure, battery storage and renewables, data centres, industrial and commercial, and residential housing. |
| E.ON UK Network Assets Ltd | Newly appointed ID pending | Smart, low-carbon connections for new developments. Works with E.ON business energy. |
| Eclipse Power Networks Ltd | 33 | New developments and connections UK-wide where developers want competitive pricing and flexible solutions. |
| Energy Assets Networks Ltd | 32 | Residential and mixed-use developments; multi-utility (electricity, gas, fibre) and smart/low-carbon projects. |
| ESP Electricity Ltd | 25 | Residential housing, I&C sites and EV charging, delivered as part of multi-utility adoption (electricity, gas, water, heat). |
| Fulcrum Electricity Assets Ltd | 35 | UK-wide local networks for residential, commercial and industrial developments, as part of Fulcrum’s multi-utility offering. |
| Green Generation Energy Networks Cymru Ltd | Newly appointed ID pending | Welsh grid and transmission-style infrastructure projects, supporting renewables and system reinforcement. |
| Harlaxton Energy Networks Ltd | 29 | Domestic, commercial and industrial customers across the UK, typically new estates and business parks. |
| Independent Distribution Connection Specialists Ltd (IDCSL) | 43 | Asset adoption and IDNO ownership for new networks nationwide, backed by H&MV Engineering’s high-voltage expertise. |
| Independent Power Networks Ltd | 24 | New-build residential and mixed-use developments, and embedded generation on its networks. |
| Indigo Power Ltd | 38 | EV charging infrastructure, residential and commercial connections, and wider network adoptions. |
| Last Mile Electricity Ltd | 26 | Residential, commercial and industrial sites as part of Last Mile’s multi-utility proposition. |
| Leep Electricity Networks Ltd | 30 | Single-developer private schemes for housing and commercial developments, often bespoke LV/11kV–33kV networks. |
| MUA Electricity Ltd | 34 | Last-mile multi-utility connections (electricity, gas, water) for residential communities and new developments. |
| Optimal Power Networks Ltd | 37 | Public electricity networks for business customers and developers, including large infrastructure and campus-style projects. |
| Stark Infra-Electricity Ltd | 39 | Metered electricity networks across multiple Grid Supply Point regions. |
| The Electricity Network Company Ltd | 27 | New housing and mixed-use developments and embedded generation. |
| UK Power Distribution Ltd | 31 | Delivers electricity to logistics parks, data centres, energy storage facilities and residential developments nationwide. |
| Utility Assets Ltd | 40 | Complex, low-carbon schemes incorporating solar, wind, storage, EV and heat networks, often seeking higher asset values and shorter connection timelines. |
| Vattenfall Networks Ltd | 36 | Large commercial and industrial sites (e.g., data centres, renewables, storage) plus other new-build developments. |
| Vital Energi Power Networks Ltd | Newly appointed ID pending | Electricity networks associated with Vital Energi’s heat and energy infrastructure projects, serving residential and commercial customers GB-wide. |
Sources: Ofgem electricity licences, and information on the individual DNO websites.
The distributor ID in the table above corresponds to the first two digits on the second line of an MPAN number.
How do IDNOs affect electricity prices
It is a common misconception that private IDNO networks result in higher bills.
In fact, Ofgem also requires that the distribution charges applied on an IDNO network are no higher than the charges an equivalent property would pay if it were connected directly to the regional DNO network.
How IDNO charges work
IDNOs earn revenue by charging suppliers Distribution Use of System fees (DUoS charges), under the same regulated model as regional DNO networks.
When an energy supplier provides a service to a customer in an IDNO region, the DUoS charge paid by the supplier is split between:
- A discounted payment to the host DNO for upstream network use.
- A smaller payment to the IDNO for the last-mile connection.
Ofgem’s Relative Price Controls require that the combined DUoS fees must always be equal to, or lower than, what a DNO-only customer would pay for an equivalent connection.
Where IDNO charges fit into electricity pricing
The DUoS charges earned by IDNOs and DNOs are not paid directly by consumers; instead, they are charged to domestic and business energy suppliers.
DUoS charges are just one of many costs incurred by energy suppliers, including TNUoS charges for using the national grid, wholesale electricity market costs and environmental levies.
Suppliers take all these underlying costs into account, as well as a profit margin, when calculating business electricity prices per kWh and business electricity standing charges for their customers.
This makes using a business electricity comparison service essential for finding the cheapest overall rates.
Ofgem and IDNO regulation
IDNOs must hold an electricity distribution licence with Ofgem and operate under the same regulatory framework as distribution network operators.
Here we summarise the key elements of Ofgem’s licence conditions:
Price controls
IDNOs must set their “use of system” charges so that they do not exceed the equivalent charges of the DNO network to which they are connected.
This protects customers in IDNO areas by ensuring they are charged the same distribution costs as other properties in their DNO region.
Safety and reliability
IDNOs are subject to the same network standards as regional electricity distribution networks. They must ensure continuity of supply, maintain their assets responsibly, respond to faults and comply with guaranteed standards for interruptions.
Ofgem monitors the performance of IDNOs through annual submissions of reliability and customer service metrics.
IDNO licencing
Ofgem’s Competition in Connections reforms mean that any organisation can apply for a distribution licence and build independent networks.
However, Ofgem’s application process assesses the financial robustness, technical competence, governance and compliance capability of new IDNOs.
IDNOs and commercial connections
Choosing one of the 24 licensed IDNOs is an increasingly popular option for businesses constructing new commercial and industrial properties.
IDNOs offer an alternative to requesting a connection from the regional distribution network operator, which can often be a slow and expensive process.
Here are the three key advantages of using an IDNO for a new commercial connection:
- Speed to energisation: Less bureaucracy than DNO processes.
- Single point of delivery: One entity manages all utilities, often also acting as an independent gas transporter.
- Capitalised Asset Value (CAV) payments – Unlike a DNO, IDNOs are typically willing to make a CAV payment to adopt high-capacity commercial connections, reducing overall connection costs.
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