Ofgem published final RIIO-ET3 guidance establishing the electricity transmission price control framework for 2026-2031. The guidance comprises 11 governance documents covering Community Funds for Electricity Transmission Infrastructure Pass-Through, Independent Technical Adviser processes, Load Use-it-or-Lose-it mechanisms, System Operator Transmission Owner Optimisation, ET2/ET3 Crossover submissions, Central Strategic Network Plan coordination, Major Projects ODI-F, Closely Associated Indirects, CSNP Re-opener, Load Re-opener, and Advanced Procurement Mechanism.

Electricity transmission network companies must use this guidance alongside the overarching Network price control 2026 to 2031 (RIIO-3) guidance to ensure compliance with their licence conditions. Companies should review all 11 associated governance documents to understand their specific obligations under the new price control period.