Our response to coronavirus

Find out how we're working to keep Great Britain’s lights on reliably throughout the outbreak.

Applying for a connection

On this page you will find details about qualifying to connect to the National Electricity Transmission System (NETS) and what you need to in order to make an application to connect.

Direct connections

These are connections to a transmission owner (TO) asset.

Transmission connected generation

In order to apply for a direct connection to the transmission system you will be required to complete all of the following:

Transmission connected demand

Demand customers applying directly to connect to the transmission system will be required to:


Interconnectors applying to connect to the transmission system will be required to:

The Interim Interconnector Connection Process document sets out the principles and proposals for the interim process of managing requests to connect interconnectors to the NETS.

The Interconnector User Guidance document sets out the agreements to sign and the process to follow for those customers who use interconnectors.


Smaller commercial and domestic connections are generally qualified as under 10 MW in Scotland and under 50MW in England and Wales. It would be unlikely for these types of customers to require an agreement with National Grid, due to the size of the project or connection. In the first instance, you should contact your local distribution company.

Embedded generation

These are connections to a distribution network operator (DNO) asset.

Small embedded generation

Small generators wishing to connect to the distribution network, that do not require explicit access rights to the NETS, will make all agreements with the DNO. However, if the DNO believes the proposed small power station may have an impact on the NETS, they may contact us.

Following this, we will assess whether there is a need to reinforce the transmission network as a result of the new distribution connection, and this is called a statement of works (SOW). The Small Embedded Generation and National Grid guidance document provides small generators and other interested parties with an understanding of National Grid’s involvement in distribution connections, and what a new generator can expect from the SOW process.

Large embedded generation

Large generation customers who are applying to connect to the distribution network are also required to have a connection offer with National Grid. Large generators are categorised as the following:

  • 100 MW or greater in National Grid’s transmission network;

  • 30 MW or greater in Scottish Power’s transmission network; and

  • 10 MW or greater in Scottish Hydro Electric’s transmission network.

The two options for this type of customer are Bilateral Embedded Generation Agreement (BEGA) and Bilateral Embedded Licence Exemptible Large Power Station Agreement (BELLA).


The BEGA states how generators will be required to comply with the: 

The BEGA will also provide the customer with transmission entry capacity (TEC) as the customer will have the right to operate in the electricity balancing market and export onto the NETS.

To apply, BEGA customers will be required to: 


The BELLA states how generators will be required to comply with the:

  • Grid Code; and

  • Connection and use of system (CUSC).

The user does not have to adhere to the Balancing and Settlement Code (BSC) because a BELLA does not automatically give the customer rights to operate in the electricity balancing market and export onto the NETS. However, it is possible for a BELLA user to actively participate in the balancing mechanism without TEC, provided the user installs the necessary hardware (EDL, EDT and control telephony). To do this, a user must request to vary the BELLA to include the relevant technical appendices. Once this is complete, the normal compliance process is followed to make sure that the relevant equipment has been installed.

To apply, BELLA customers will be required to:

An image of screen displays inside a control room

Registers, reports, and guidance

Go to the Registers, reports, and guidance page for connection registers, reports, policy updates, and industry guidance documents for understanding the connection process.  

Find out more


Understanding the application process

Technical data

In addition to the Data Registration Code (DRC), our DRC Tool provides a list of essential data fields that will be required when you submit a connection application.


To understand the costs associated with connecting to the NETS, please refer to the Charge Modeller and Application Fee Calculator document. The Charge Modeller provides an indicative cost for the annual connection charge for new assets being installed and allows you to create hypothetical scenarios based on various factors. The Application Fee Calculator calculates the cost of an application fee based on the location of the connection, size of connection and offer type.


This provides a consistent methodology for Generation Customers to provide financial security for the transmission reinforcement works their connection triggers and has been codified in Section 15 of the Connection and use of System Code (CUSC) as a result of CUSC Modification Proposal 192, 219, 222 & 223.

These documents will help you better understand the securities process:

A Guide to Security Provision

CMP192 Updated Guidance Document

These templates will help for various options when posting securities:

Cancellation Charge - Letter of Credit

Cancellation Charge - PCG -Fixed Term Fixed Amount

CUSC - Insurance Bond

CUSC - Insurance Performance Bond

Termination Amount - Letter of Credit

Termination Amount - Parent Company Guarantee

Use of System - Letter of Credit

Use of System - Guarantee 

Use of System - Parent Company Guarantee

These arrangements replace the Final Sums methodology and the Interim Generic User Commitment Methodology for Generation and Interconnector Customers. The Final Sums methodology continues to apply for the Demand Customers.


Interactive Offer Policy applies where an offer for connection to a customer is due to be made but it would affect the terms of another open offer reliant upon the same transmission reinforcement works.

We have published guidance for managing interactive offers which will explain the process we follow to allocate capacity in these circumstances:

Policy Document for Managing Interactive Offers

A waterfront view of the London Bridge at dusk with well-lit buildings in the background

Connection and Use of System Code (CUSC)

The CUSC is the contractual framework for connection to, and use of, the National Electricity Transmission System (NETS).

Find out more

A view through a tunnel to show wind turbines at sunset

After you have connected

How to modify a connection, how to disconnect, and details of the compensation process for loss of access.

Find out more

A day-time shot of a busy city scene with the sun casting a bright light over a street


To find out more about charges and how those charges are determined, please go to the Charging section of the website.

Find out more