ICP and IDNO connections

How an independent connection provider, adopting network operator and host DNO divide the design, construction, ownership and operation of a new electricity connection.

An Independent Connection Provider, or ICP, can design and build eligible parts of a new or modified electricity connection. An Independent DNO, or IDNO, is licensed by Ofgem to own and operate a local distribution network.

The simple distinction is that an ICP is a delivery contractor and an IDNO is a network owner. They can be companies in the same group, but the contracts, accreditations and responsibilities still need to be identified separately.

The regional DNO remains involved because the new assets ultimately connect to its wider network. Appointing an ICP or IDNO does not allow the project to bypass the host network’s capacity, safety or connection requirements.

The three roles

Independent Connection Provider

An ICP must hold National Electricity Registration Scheme accreditation for the particular work it will undertake. NERS scopes differ by activity and voltage, so finding a company on the register is only the first check. Its live accreditation must cover the design, project management, cable, jointing, substation or operational work required by the scheme.

The ICP may design, procure and construct the contestable works. It does not become the enduring network operator merely by building them. Completed adoptable assets transfer to the DNO or IDNO under the relevant adoption arrangements.

Independent DNO

An IDNO holds an electricity distribution licence. It can adopt, own, operate, maintain and repair an embedded network connected to a regional DNO, including the local cables and substations serving a development.

It is not the electricity supplier. End users still buy electricity from a supplier, and the IDNO’s ownership of the local wires does not itself prevent supplier switching.

Host DNO

The host DNO operates the regional network to which the new connection attaches. It provides the non-contestable services and must be satisfied that the interface with its network is safe and technically acceptable. Depending on the scheme and the ICP’s authorisations, it may also approve designs, carry out reinforcement, make the final live connection or adopt the completed assets itself.

Contestable and non-contestable work

“Contestable” describes connection work for which the customer can choose an appropriately accredited provider. “Non-contestable” work remains with the host DNO because it involves the existing network, system information, safety control or another function that cannot be opened to competition in that case.

Contestable work can include:

connection design and specification
materials and plant procurement
trenching, ducts and reinstatement
laying and jointing new cables
building and equipping substations
testing, records and as-laid drawings
some work on or connection to existing assets where the ICP has the necessary agreement and authorisation

Non-contestable work can include:

assessing the effect on the host network
network reinforcement that remains reserved to the DNO
approving or reviewing the point of connection and design where self-determination or self-approval is not available
work requiring operational control of existing live equipment
final connection activities outside the ICP’s authorised scope

There is no reliable nationwide table that assigns every task the same way. DNO charging methodologies, market segment, voltage, scheme type, accreditation and any extension-of-contestability agreement all affect the boundary. Obtain a project-specific scope from the host DNO and make it a contract document.

The point of connection is still a network decision

The point of connection, or POC, is where the new network attaches to the existing distribution system. Some ICPs can identify a POC or approve their own design within defined market segments under agreements with the DNO. That is a controlled extension of contestability, not a general right to choose any convenient connection point.

The host DNO still supplies network data and can require a different solution where the proposal does not meet its rules. Larger demand, generation, storage and higher-voltage schemes are more likely to need direct network assessment and site-specific agreements.

Do not price or programme the build from an assumed POC. Secure the accepted connection basis, including import capacity, export capacity, voltage, fault level, earthing, reinforcement and any flexible connection terms.

Two common adoption routes

DNO adoption

The ICP constructs the agreed contestable assets for adoption by the regional DNO. The framework and site-specific adoption documents allocate design responsibility, inspection, live working, transfer of assets and defects. On adoption, the DNO becomes responsible for the adopted network.

IDNO adoption

The ICP constructs an embedded network for an IDNO to adopt. The IDNO and host DNO also need an agreement covering the connection between their networks. The IDNO then owns the adopted local network and is responsible for its continuing operation, maintenance and fault response.

In either route, commissioning is not the same as adoption. Check the conditions that must be completed before asset transfer, energisation and MPAN registration. Until those hand-offs are documented, responsibility for defects, insurance and access may be unclear.

Asset-value offers

An IDNO may make an asset-value or adoption offer because it expects future revenue from operating the local network. That can reduce the developer’s net connection cost, but it is a commercial offer rather than a universal regulated rebate.

The headline payment is not enough to compare bids. Establish:

who receives the payment: developer, ICP or another project company
which assets and connected loads the valuation assumes
when the payment becomes due
whether it changes if the development is delayed, rephased or built differently
whether occupancy, energisation or consumption conditions apply
whether any amount can be withheld or clawed back
who funds variations, abortive work and defects
the land rights, warranties and security required by the adopter

Compare the complete connection and adoption package. A higher asset-value offer can be outweighed by different construction prices, legal obligations, security requirements or programme risk.

Network charges after adoption

IDNOs recover revenue through distribution charges within the electricity-market arrangements. Ofgem’s relative price-control framework discounts the charge an embedded local network pays to the host DNO to recognise that the IDNO provides the “last mile”.

Under the licence position described by Ofgem, an IDNO may charge domestic customers no more than the equivalent DNO tariff. Ofgem also notes that only domestic charges have that direct licence cap; non-domestic and higher-voltage projects should examine the published charging methodology and connection terms rather than assuming identical treatment.

The distribution charge is not a separate household invoice from the IDNO in the normal supplier arrangement. It forms part of the industry charges recovered through the electricity supply chain.

Generation, storage and later changes

An IDNO-connected property still follows the applicable G98, G99 and G100 processes. The application or notification goes to the network operator responsible for the connection. The IDNO may need to consult its host DNO where the proposed import or export affects the upstream network.

For a development with solar, batteries, EV charging or heat pumps, record both the individual-premises limits and any site-wide limits. A dwelling’s cut-out rating is not evidence that the whole development has unrestricted upstream capacity.

Later changes should start with the current network owner. Do not send an application to the regional DNO merely because its name is familiar if an IDNO owns the local network. The MPAN distributor identifier, connection documents and network-operator lookup can help identify the correct party.

Project record

Keep a clear responsibility schedule alongside:

the accepted POC and connection offer
the ICP’s relevant NERS scopes and subcontractor arrangements
the contestable and non-contestable works schedule
design approvals or self-approval evidence
host-DNO network access and live-working agreements
the adoption agreement and any IDNO bilateral agreement
land rights for cables and substations
inspection, testing and as-built records
energisation conditions and MPAN schedule
asset-value terms and payment evidence
defects, warranty, access and emergency contacts

The party coordinating the project should track each dependency. An ICP, IDNO and DNO can each be performing correctly while the connection still stalls at an unowned interface between them.

For an existing home on an IDNO network

The practical questions are simpler:

use the network-operator details on the bill, MPAN records or ENA lookup for power-cut and connection matters
continue to use the electricity supplier for tariffs, bills and metering
send solar, battery, EV-charger and supply-upgrade enquiries to the actual network owner
keep any IDNO acknowledgement or approval with the installation records

The presence of an IDNO is not, by itself, a reason a supplier switch or domestic low-carbon installation should fail. It does mean the installer must identify the correct network route and allow for any necessary host-DNO consultation.