Reflecting on TNUoS increases from April 2026
Written by Jonathan Corbishley, Head of Commercial at SmartestEnergy Business. With more than a decade of experience across energy trading, forecasting, hedging and commercial risk management, Jonathan shares insights into rising TNUoS charges and their impact on business energy costs.
For many businesses, managing energy costs has become an increasingly important part of financial planning. While wholesale energy prices often attract the most attention, non-commodity charges can also have a significant impact on overall energy bills.
In this edition of our Smartest Insights series, Jonathan Corbishley, Head of Commercial at SmartestEnergy Business, shares his perspective on the latest TNUoS charge increases and what they mean for businesses navigating an increasingly complex energy landscape.
As Jonathan explains:
From 1 April 2026, the latest increases to TNUoS charges will come into effect, bringing another round of unavoidable cost pressure across the UK business energy market.
Understanding what is driving these changes and how they affect energy contracts can help businesses plan more effectively and avoid unexpected surprises.
What are tnuos charges?
TNUoS stands for Transmission Network Use of System charges.
These charges help fund the operation, maintenance and development of Great Britain's high-voltage electricity transmission network. The network plays a critical role in transporting electricity from generators to regional distribution networks before it reaches homes and businesses.
Unlike wholesale electricity costs, TNUoS charges are regulated and sit outside the control of energy suppliers. However, they remain an important component of the overall cost of supplying electricity.
As investment continues across the UK's electricity infrastructure to support energy security and the transition towards a lower-carbon future, network-related costs continue to evolve.
Why are tnuos charges increasing?
The UK's electricity network is undergoing significant transformation.
Investment is needed to support increasing electricity demand, connect new renewable generation assets and improve the resilience of the system. These infrastructure upgrades are essential to delivering a more secure and lower-carbon energy system.
However, the costs associated with maintaining and expanding the network are ultimately recovered through regulated network charges, including TNUoS.
While these charges are not determined by suppliers, they can still influence the overall cost businesses pay for electricity.
The impact on business energy costs
The latest TNUoS increases arrive at a challenging time for many organisations.
Businesses across the UK continue to manage rising operational costs, margin pressures and economic uncertainty. Any increase in non-commodity costs can therefore create additional pressure on budgets and forecasting.
Jonathan highlights the challenge:
As regulated, non-commodity charges, TNUoS sits entirely outside of supplier control. Yet, as suppliers, we remain at the frontline, responsible for explaining these changes, absorbing operational complexity and ultimately making the difficult decision to pass these increases through to our valued customers.
This makes transparency around energy costs increasingly important for both customers and suppliers.
Why communication matters
One of the biggest frustrations businesses face is unexpected cost increases.
Clear communication helps organisations understand what is changing, why it is changing and how it may affect their overall energy strategy.
According to Jonathan:
Expectation management is critical. Clear, proactive engagement allows businesses to plan ahead, avoid unexpected cost shocks and maintain confidence in their energy partnerships.
For businesses reviewing budgets, procurement strategies or future contracts, early visibility of market changes can support more informed decision-making.
Supporting brokers and TPI partners
The impact of TNUoS increases extends beyond suppliers and customers.
Energy brokers and Third Party Intermediaries (TPIs) play an important role in helping businesses understand market developments and navigate energy purchasing decisions.
Jonathan notes:
These changes affect the conversations they're having every day, and it's essential that we equip them with clear information, timely updates and the support they need to guide their clients effectively.
Providing consistent, transparent information helps ensure customers receive the guidance they need as market conditions evolve.
Planning ahead for TNUoS charge increases
The latest TNUoS charge increases highlight the growing importance of understanding all components of a business energy bill, not just wholesale electricity costs.
As the UK continues to invest in a more resilient, secure and lower-carbon electricity system, network charges will continue to evolve. While these regulated costs sit outside supplier control, businesses that stay informed and work closely with trusted energy partners are better positioned to plan ahead and manage the impact of change.
Clear communication is critical. Understanding what's driving rising costs can help businesses avoid unexpected budget pressures, improve financial planning and make more informed energy decisions.
As Jonathan explains:
Our commitment remains constant: complete transparency around regulated costs, honest conversations about market realities and practical support to help our customers and partners navigate change.
At SmartestEnergy Business, we believe transparency helps build confidence. By providing clear explanations of market developments and regulated cost changes, we aim to help businesses navigate the evolving energy landscape with greater certainty and confidence.
About the author
Jonathan Corbishley is Head of Commercial at SmartestEnergy Business and has more than a decade of experience working across energy trading, forecasting, hedging and commercial risk management.
Jonathan has held senior commercial and trading leadership positions throughout his career, helping businesses navigate wholesale market volatility, non-commodity costs and changing energy market regulations. His expertise spans electricity and gas demand forecasting, energy hedging strategies, risk management and commercial operations.
At SmartestEnergy Business, Jonathan oversees commercial strategy and works closely with customers, brokers and industry stakeholders to help businesses better understand market developments and make informed energy decisions. His insights are grounded in extensive experience managing the complex factors that influence business energy costs across the UK market.
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