UNC Transportation Principal DocumentDocument files listed below. General Offtake Arrangements Document Transportation Principal Document European Interconnection Document Independent Gas Transporter Arrangements Document Code Updates Printer friendly version Related Files File 11 April 2025 Transportation Principal Document (Consolidated, printable version) File 01 June 2017 TPD Front Cover File 01 April 2017 TPD Table of Contents File 01 October 2024 TPD Section A - System Classification File 24 March 2025 TPD Section B - System Use and Capacity File 24 March 20205 TPD Section C - Nominations File 09 September 2024 TPD Section D - Operational Balancing and Trading Arrangements File 24 March 2025 TPD Section E - Daily Quantities Imbalances and Reconciliation File 01 October 2024 TPD Section F - System Clearing, Balancing Charges and Neutrality File 16 December 2024 TPD Section G - Supply Points File 01 October 2024 TPD Section H - Demand Estimation and Demand Forecasting File 11 April 2025 TPD Section I - Entry Requirements File 13 April 2023 TPD Section J - Exit Requirements File 29 March 2023 TPD Section K - Operating Margins File 01 October 2024 TPD Section L - Maintenance and Operational Planning File 16 December 2024 TPD Section M - Supply Point Metering File 29 March 2023 TPD Section N - Shrinkage File 01 October 2024 TPD Section O - System Planning File 09 September 2024 TPD Section Q - Emergencies File 29 March 2023 TPD Section R - Storage File 09 September 2024 TPD Section S - Invoicing and Payment File 01 April 2017 TPD Section U - Not Used File 11 April 2025 TPD Section V - General File 09 September 2024 TPD Section X - Energy Balancing Credit Management File 01 October 2024 TPD Section Y - Charging Methodologies Download All Files