Businesses are now facing a confirmed sharp rise in network charges as the RIIO-3 regulatory framework takes effect this April 2026. With Ofgem’s Final Determinations now published, the scale of the infrastructure levy is clear.
The latest figures point to significant increases across standing charge elements—the non-commodity costs that appear on every electricity bill regardless of how much energy you use.
Why are TNUoS costs increasing?
The rise coincides with the launch of RIIO-3, Ofgem’s five-year regulatory framework for the transmission network.
In December 2025, Ofgem gave the final go-ahead for £28.1 billion in network investment. This funding allows Transmission Operators (including National Grid, Scottish Power, and SSEN) to deliver over 80 major infrastructure projects needed to meet the UK’s Net Zero targets and ensure long-term energy security. This approved cost base is now being filtered directly into business TNUoS rates for the 2026/27 period.
What the confirmed rates show
Data from the National Energy System Operator (NESO) published this month (January 2026) confirms the impact:
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Average Increase: While the initial "90% increase" forecasts were mitigated by Ofgem’s revenue smoothing, industry-wide TNUoS costs are still rising by an average of 60%–65%.
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Fixed Realities: These rates are now a fixed reality for the upcoming financial year.
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Regional Impact: Because TNUoS is locational, businesses in constrained areas or those further from generation sources may see even higher variances.
What businesses should do now
Even though these changes won’t appear on invoices until the April billing cycle, the window for proactive budgeting is closing. Energy costs are no longer driven purely by the wholesale "commodity" market, in fact, non-commodity costs now account for more than 60% of a typical business electricity bill.
Here is your 3-step action plan:
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Audit your Banding: With rates now finalized, ensuring your site is in the correct kVA/Voltage band is critical. Being in the wrong band will be significantly more expensive under the new 2026 rates.
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Verify Pass-Throughs: Review your current contracts to ensure these new regulatory costs are being applied correctly and transparently.
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Update 2026 Budgets: Ensure your Q2 financial planning accounts for a 5%–10% increase in total electricity spend driven purely by these network changes.
The Resolve View
The upcoming TNUoS changes are a stark reminder that non-commodity costs, not just energy prices, can move markets. By staying proactive, businesses can avoid exposure to volatility and make strategic decisions ahead of the April reset.
The April 2026 reset is now just weeks away. Would you like us to run a complimentary'Band Audit' on your current sites to see if we can lower your fixed exposure before the new rates hit?
If you're looking to save money on your business gas bills then why not get in touch today? The close relationships Resolve Energy has developed with over 24 of the UK’s biggest business energy suppliers allows our energy experts to source the best business gas rates available for your company right when you need them. Request a free quote today and start saving money on your energy.
