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


Friday 1 February 10:30-11:30am



TNUoS T&T Model training


Wednesday 5 December 10:00am-2:00pm

Password: NG504_001

Network charging developments and Charging Futures

Our work considering a Targeted Charging Review and how we are working with Ofgem and others to ensure a coordinated approach with other network charging initiatives.

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

Tools and calculators

The current charging calculations are based on the Oct 2014 TEC register. To view the latest Transmission entry capacity (TEC) register please refer to the Registers, reports, and guidance page.


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.