Transmission Network Use of System (TNUoS) Charges
TNUoS charges recover the cost of installing and maintaining the transmission system in England, Wales, Scotland and Offshore.
Who does this charge apply to?
✓ Generators
✓ Suppliers
✓ Directly connected Transmission demand
✕ Distribution Network Operators
✓ Embedded Generators*
✕ Interconnectors
On this page you will find information related to TNUoS charges, such as guidance on who these charges apply to and how/when these charges are billed. Our latest and historical TNUoS publications and other relevant documentation are provided, along with ways to interact with the tariff setting process, ask questions and provide feedback.
*Certain embedded generators (<100MW) receive export payments over triad
How am I charged?
Generators are charged according to TEC (Transmission Entry Capacity). Suppliers are charged based on 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.
Events
When we publish our latest forecasts of TNUoS tariffs, we are committed to holding webinars to talk through our publications and take your questions.
Click on our upcoming and recent webinars to register or view the presentations and access the webinar recordings. We will also be holding TNUoS Tariff & Transport (DLCF ICRP) Model training sessions, details of how to sign up will be posted here.
TNUoS Tariffs August Forecast (2023/24)- Webinar recording and slides
We held a webinar on 22nd Sep to go through the key messages from the latest forecast and to hold a Q&A session. Q&A document will be uploaded separately, once ready.
TNUoS 5-Year View Tariffs Webinar (14 April 2022) Q&A Document
The TNUoS 5-Year View (2023/24 - 2027/28) Q&A document has been published. We held an industry Webinar 14 April 2022 to go through the reports key messages and to hold a Q&A session. Click here to go to the finalised Q&A document.
TNUoS 5-Year View Tariffs Webinar (14 April 2022) Slide Pack and Recording
The TNUoS 5-Year View (2023/24 - 2027/28) tariff report has been published. We held an industry Webinar 14 April 2022 to go through the reports key messages and to hold a Q&A session. Click here for Webinar slides and a link to the recorded Webinar.
TNUoS 2022/23 Final Tariff Report published
Report Published 31 Jan 2022, Click here to see the report (tariff tables file available in the '2022/23 Tariff Publications'
TNUoS 2022/23 Draft Tariffs webinar recording and slides
Report Published: November 2021 Webinar: 14 December 2021 - Webinar and slide pack available to view, click link above.
TNUoS Tariffs (2022/23 – 2026/27) 5-Year View webinar recording and slides
Report Published: April 2021 Webinar: 13 May 2021
2021/22 Final Tariffs webinar recording and slides
Report Published: January 2021 Webinar: 16 February 2021
2021/22 November Draft Tariffs webinar recording and slides
Report Published: November 2020 Webinar: 10 Dec 2020
Latest news and updates
TNUoS Tariffs April 2022 5-Year View (2023/24 - 2027/28) published
We have recently published our 5 Year-view (2023/24 – 2027/28) on TNUoS Tariffs – go to the TNUoS tariffs and notifications of changes section.
TNUoS 2022/23 Final Tariffs Report Published
Published 31 January 2022: The report is now available, to view the tariff tables file go down to the '2022/23 Tariff Publications' under the 'TNUOS tariffs & notifications of changes' section
TNUoS Tariffs April 2021 5-Year View published
We have recently published our 5 Year-view (2022/23 – 2026/27) on TNUoS Tariffs – go to the TNUoS tariffs and notifications of changes section.
ESO 2021/22 Charging Statement published
The ESO Charging statement ‘Issue 3 revision 0’ for charging year commencing 1 April 2021 has been published.
Timetable of TNUoS forecast for 2022/23 updated
The timetable for our 2022/23 TNUoS tariff publications during 2021/22 has been updated.
TNUOS tariffs & notifications of changes
The documents below 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).
2023/24 Tariff Publications
2022/23 Tariff Publications (Current year tariffs)
| Name | Published Sort ascending |
|---|---|
| Final Specific ALFs 2022-23 - Table | 23 Mar 2022 |
| Final Specific ALFs 2022-23 - Report | 23 Mar 2022 |
| January 2022-23 TNUoS Final Tariffs - Webinar (Slide Pack and Link to Recording) | 15 Feb 2022 |
| Final TNUoS Tariffs for 2022-23 – Tables | 31 Jan 2022 |
| Final TNUoS Tariffs for 2022-23 – Report | 31 Jan 2022 |
| November Draft 2022-23 TNUoS Tariffs - Webinar | 21 Dec 2021 |
| November Draft TNUoS Tariffs for 2022-23 – Tables | 30 Nov 2021 |
| November Draft TNUoS Tariffs for 2022-23 - Report | 30 Nov 2021 |
| Draft ALFs for 2022-23 | 17 Nov 2021 |
| August Forecast TNUoS Tariffs for 2022-23 - Tables | 31 Aug 2021 |
2021/22 Tariff Publications
Tariff Publications - Archive (Pre 2021/22)
| Name | Published Sort ascending |
|---|---|
| 2021-25 August 5YV TNUoS Tariff Webinar and Recording | 23 Sep 2020 |
| Final TNUoS Tariffs for 2020-21 - Report - Updated | 4 Mar 2020 |
| TNUoS 2020-21 Final Tariff Webinar | 13 Feb 2020 |
| Final TNUoS Tariffs for 2020-21 - Tables | 31 Jan 2020 |
| November Draft TNUoS Tariffs for 2020-21 - Webinar slides and recording | 14 Dec 2019 |
| Final ALFs for 2020-21 | 29 Nov 2019 |
| November Draft TNUoS Tariffs for 2020-21 - Report | 29 Nov 2019 |
| November Draft TNUoS Tariffs for 2020-21 - Tables | 29 Nov 2019 |
| Draft ALFs for 2020-21 | 25 Oct 2019 |
| July Forecast TNUoS Tariffs for 2020-21 - Webinar slides and recording | 15 Aug 2019 |
5-Year View Tariff Publications
Tariff change notifications
| Name | Published Sort ascending |
|---|---|
| 150 Day Notice for 2023-24 Charges | 3 Nov 2022 |
| 150 Day Notice for 2022-23 Charges | 21 Oct 2021 |
| 150 Day Notice for 2021-22 Charges | 28 Oct 2020 |
| 150 Day Notice for 2020-21 Charges | 17 Oct 2019 |
| 150 Day Notice for 2019-20 Charges | 23 Oct 2018 |
| 150 Day Notice for 2018-19 Charges | 12 Oct 2017 |
| 150 Day Notice for 2017-18 Charges | 21 Jun 2017 |
| 150 Day Notice for 2016-17 Charges | 29 Oct 2015 |
| 150 Day Notice for 2015-16 Charges | 29 Oct 2014 |
| 150 Day Notice for 2014-15 Charges | 11 Jun 2013 |
Learn more about TNUoS
Use the ESO Data Portal to gain access to TNUoS tariff datasets that are geared towards API compatibility, providing additional flexibility to end users of tariff data.
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
Triads are the three half-hour settlement periods with highest system demand. Learn more about Triads and access related data and guidance materials
Additional help and support
Access a range of guidance materials to help you understand how, when and what you’ll be charged.
Contact us directly to raise a query relating to TNUoS and our publications, or to provide feedback. Please note our usual contact number is currently unmanned due to COVID-19 homeworking.
Join our mailing list to receive publication updates, invitations to our forums, webinars and workshops, and links to our latest guidance materials.