Skip to main contentOn 30th January, the National Energy System Operator (NESO) issued the final Transmission Network Use of System (TNUoS) tariffs for the 2026-27 charging year. These final tariffs confirm a significant increase in TNUoS charges for businesses, with average charges rising by around 60% compared to current levels.
While the final figures are very close to the draft tariffs issued previously, they remain substantially higher than those currently levied. The fixed residual tariff, which makes up more than 90% of the charge faced by consumers, is approximately 0.75–0.76% lower than the draft figure shared by NESO.
Although the final tariff is slightly lower than the draft, businesses will still see a substantial increase in costs compared to current charges. These new tariffs will take effect from 1st April 2026.
What are TNUoS charges?
Transmission Network Use of System (TNUoS) charges are designed to recover the cost of operating, maintaining, and expanding the electricity transmission network across England, Wales, Scotland, and offshore. These costs are passed through to consumers via electricity bills. From April 2026, many businesses will see year-on-year increases in TNUoS charges of more than 60%.
Confirmed Changes
- Final 2026/27 Tariffs confirm a 60% increase in TNUoS charges for businesses
- Business electricity bills may rise by an estimated 5–10%, depending on consumption and location.
- Over the next five years, TNUoS charges are projected to rise by around 69%
- The next set of 2027-28 forecasts will be released by NESO in April 2026.
Why is this increase happening?
The rise is primarily driven by the scale of investment needed to upgrade the electricity grid to support more renewable generation, which is being accelerated by the UK government’s push towards net zero by 2050.
TNUoS charges fund Transmission Owners (TOs), who are responsible for owning, operating, and maintaining high-voltage infrastructure such as pylons and substations.
The sharp rise in allowed revenue is largely linked to the RIIO-ET3 price control, with revenue expected to grow from around £4bn in 2025/26 to over £10bn by 2030/31. Recent charging rule changes, including CMP463, have also been incorporated into the final 2026/27 figures.
When will TNUoS price rises take effect?
This forecast covers the charging period from 2026/27 through to 2030/31 and will come into effect 1st April 2026. They have no impact on the current 2025/26 charging year.
What this means for businesses
For most business energy users, the increases will impact standing charges – the fixed part of the electricity bill. This means businesses may face higher costs regardless of how much energy they consume. Budgeting, forecasting, and procurement strategies should take these changes into account.
If you’d like to understand how the confirmed TNUoS changes could affect your business or discuss ways to manage rising non-commodity costs, please get in touch with our team.
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