Article

Ofgem's Final Determinations for RIIO‑ET3 indicate that allowed revenue for transmission owners will rise from approximately £4 billion in 2025/26 to over £10 billion by 2030/31, resulting in a significant increase in TNUoS charges starting April 2026. This increase will affect all electricity users, with sectors such as data centers, manufacturers, and logistics facing the largest percentage increases.

Average increases per meter are projected between £17,000 and £82,500, with some individual site increases exceeding £300,000. Businesses should assess their TCR banding, improve energy efficiency, consider on-site generation, and manage portfolio-level risks.

Ofgem forecasts a 5 to 10 percent increase in business electricity costs for 2026 to 2027, while gas network charges will also rise. Energy suppliers will vary in how they incorporate these changes into contracts, leading to potential short-term uncertainties for businesses.