We are a separate company

On 1 April the Electricity System Operator became a legally separate company within the National Grid Group. Find out more about what this change means.

Transmission Network Use of System (TNUoS) charges

Transmission Network Use of System (TNUoS) charges recover the cost of installing and maintaining the transmission system in England, Wales, Scotland and Offshore.

How am I charged?

Generators Suppliers
Charged according to your TEC (Transmission Entry Capacity) Charged based on your actual demand

All tariffs are based on which geographical zone Users are connected to.

TNUoS tariffs are published annually by 31 January and take effect from 1 April each year.

TNUoS tariffs 

Dates of our next publications and webinars

Get involved

Whenever we publish our forecasts and five-year views of tariffs, we hold webinars to talk through the documents and take your questions. 

TNUoS Tariff Report

Date of Publication


Date of Event


2020/21 – 2023/24 5 Year Forecast

Mid September 2018


Thursday 20 September 10:00-11:00am

Play Recording

2019/20 Draft Tariffs

End of November 2018


Wednesday 12 December 10:30-11:30am

Webinar and slides

2019/20 Final Tariffs

End of January 2019


Wednesday 6 February 10:30-11:30am

Play recording
2020/21 - 2024/25 5 Year ViewEnd of March 2019WebinarThursday 4 April 13:30-14:30pmWebinar and slides


TNUoS tariffs and notifications of changes

These documents contain the TNUoS tariff forecasts and notifications of tariff changes. Updates for next year's tariffs are published quarterly in accordance with the Connection and Use of System Code (CUSC). Updates for the next five years’ tariffs are published annually. 

TNUoS Tariff Model 

(DCLF ICRP Transport Model)

We publish the DC Load Flow Investment Cost Related Pricing (DCLF ICRP) Transport Model which allows users to undertake their own sensitivity analysis of generation and demand tariffs under different scenarios.

If you'd like a copy of the DCLF ICRP Transport Model, contact us.

For more detailed information on the DCLF ICRP, please see Chapter 2 of The Statement of the Use of System Charging Methodology in Section 14 of the CUSC.

Get involved in our TNUoS Tariff Model Training sessions

We run regular in-house training sessions, to give participants hands-on experience at changing the model inputs and generating their own scenarios.

Who are the sessions aimed at?

Users who have some understanding of the TNUoS tariffs, and have little or no previous experience at using the DCLF-ICRP model.

Our sessions run from 10:00am-2:00pm

Use the links below to register (password is NGeso504_001)
Thursday 9 MayRegister
Wednesday 14 AugustRegister
Thursday 19 SeptemberRegister

Generation zoning reviews

We undertake reviews of generation tariff zones at the start of the Price Control period unless there is a significant change in the generation background. These documents contain consultation details of previous reviews.

Charging statements

The charging statements describe our charges and the methodologies behind them. The Use of System Charging Methodology Statement and the Connection Charging Methodology Statement are included within Section 14 of the Connection and Use of System Code (CUSC)