On this page you will find guidance materials to help you understand how, when and what you'll be charged. 

The methodology we use to set tariffs and calculate charges is in the Connection and Use of System Code (CUSC), Section 14. 

Would you like to get involved?

Join our mailing list to receive invitations to our forums, webinars and workshops, and links to our latest guidance materials.

Join our mailing list

TNUoS guidance

Name
Guidance - Transmission Demand Residual Tariffs
Guidance - Calculation of the Generator TNUoS Adjustment Tariff for the purposes of the Limiting Regulation 2023/24
T and T Model Training Videos
Guidance - TNUoS demand zone for DCCs
Guidance - TNUoS onshore local circuit charges
Guidance - TNUoS modelling for 3 ends HVDC circuits
Guidance - TNUoS Onshore Locational Security Factor
TNUoS DCLF ICRP (TnT) Model Training - Presentation
TNUoS tariffs for suppliers (includes link to recorded webinar)
What are Transmission Losses?

2019 Forum materials

Name
Charging Forum - Questions and Answers
Workshop slides - Forecasting performance variation (FPVAR)
Workshop slides - How and why we reconcile your TNUoS charges (generation)
Workshop slides - How and why we reconcile your TNUoS charges (demand)
Workshop tool - Forecasting performance variation (FPVAR) calculator
Workshop tool - Generation reconciliation calculator
Workshop tool - Demand reconciliation calculator
Charging Forum - Glossary of terms
TNUoS Wider Tariffs handout
Workshop slides - Connection Charges Explained

2018 Forum materials

Name
TNUoS tariffs and forecasting (includes link to recorded webinar)
TNUoS charging and billing (includes link to recorded webinar)
BSUoS reporting and forecasting (includes link to recorded webinar)
BSUoS billing (includes link to recorded webinar)
Your questions answered - from the October 2018 Forums
Charging and Settlement Forum Generation-focused Day Slides 17 October 2018
Charging and Settlement Forum Demand-focused Day Slides 16 October 2018