We are becoming a separate company

In April 2019, the Electricity System Operator is becoming a separate company within the National Grid Group. Find out more about what this change will mean.

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. Generators are charged according to their TEC.  Suppliers are charged based on their demand forecast. 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 tariff forecasts 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. The TNUoS tariffs for 2017/18 can be found below and are now fixed.

 For the 2019/20 TNUoS tariffs, the timetable for our upcoming forecasts is outlined below:

Timetable updates

TNUoS Tariff Report

Date of Publication


Date of Event


2019/20 Quarterly Forecast

End of April 2018


Friday 11 May 1:30-2:30pm

Play Recording 

2019/20 Quarterly Forecast

End of June 2018


Friday 6 July 10:30-11:30am

Play Recording

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


Our TNUoS Tariff Model Training sessions are aimed at users who have some understanding of the TNUoS tariffs, and have little or no previous experience at using the DCLF-ICRP model. This training session will be useful if you’re a TNUoS customer, who would like to know how to change the model inputs, and how to run the model to generate your own scenarios.

TNUoS Transport & Tariff Model training


Thursday 21 February 10:00am-2:00pm

Password: NGeso504_001
Thursday 9 May 10:00am-2:00pmRegister
Password: NGeso504_001
Wednesday 14 August 10:00am-2:00pmRegister
Password: NGeso504_001
Thursday 19 September 10:00am-2:00pmRegister
Password: NGeso504_001

2020/21 charging year tariff forecasts

Network charging developments and Charging Futures

Our on-going involvement with Charging Futures is part of our commitment to improve competition in markets. By making it easier to understand and get involved in charging reforms, Charging Futures supports equality in network charging.

Find out more

Balancing Services Use of System (BSUoS) charges

BSUoS recovers the cost of day-to-day operation of the transmission system. These charges apply to suppliers and generators.

Find out more

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.

TNUoS charging statements

TNUoS charging statements are documents describing 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). National Grid administers the CUSC. Changes to the CUSC are subject to industry consultation, approved either by Ofgem or the CUSC Modification Panel.

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.

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.

If you would like a copy of the DCLF ICRP Transport Model, require further information on the charging methodologies and principles, or have any other charging enquiry, please contact our Charging Team at [email protected] or 01926 654633.