The April 2026 TNUoS Spike: What Your Business Needs to Know
If you’ve reviewed your electricity forecasts for the new financial year, you may have already noticed a significant jump in the non-commodity section of your bill. From 1 April 2026, a national network charge called Transmission Network Use of System (TNUoS) is increasing more steeply than ever before and will affect every UK business.
This isn’t a supplier-added fee, and it’s not something you can ‘opt out’ of. However, how you manage it can make a meaningful difference to your budget.
What is TNUoS?
TNUoS is the fee your business pays to use the high-voltage electricity network, the system that carries power from generators across the country to your region.
These charges fund essential national upgrades, including:
- The Great Grid Upgrade: Expanding the network to handle more renewable energy
- Modernisation: Replacing aging infrastructure to keep the UK’s power supply resilient
- RIIO-3 investment: Supporting Ofgem’s new 5-year regulatory framework for a net zero future
Why are costs rising so sharply in 2026?
To meet the UK’s clean-power goals by 2030, the National Energy System Operator (NESO) has confirmed that the revenue needed to maintain the Grid must increase significantly.
Here’s what that means for your business:
- TNUoS charges are increasing by 61%-64% on average this year
- Over 90% of the cost is now a fixed residual charge, meaning usage reductions won’t reduce your standing charge
- TNUoS’ share of a typical energy bill is expected to grow from 7% today to 12-15% by the end of the decade
- Sites in South Wales, the South West and the South East will see some of the steepest increases due to their distance from key generation hubs
How This Affects You (and What You Can Do About It)
Although TNUoS is a national charge, being in the wrong capacity band can mean you’re paying far more than necessary. That’s where our expertise protects your bottom line.
- kVA Capacity Reviews & Banding Audits
Your TNUoS charge is partly determined by your TCR Band, which is linked to your site’s Available Capacity (kVA) – the amount of grid space you’ve reserved.
If your capacity is set higher than your actual usage, you could be overpaying every day.
Our team reviews your real demand profile, identifies the correct kVA level, and can negotiate reductions on your behalf. A simple change in banding can create substantial annual savings.
- Dedicated Account Management (No Call Centres)
When these new rates hit your invoice, you shouldn’t have to wait in a phone queue to speak to an automation. Every Stadia client has a dedicated account manager who knows your sites, your usage and your commercial pressures – and can break down complex regulation in minutes, not hours.
- Forensic Invoice Auditing
With charges rising sharply, billing errors are becoming more common. We audit invoices line by line to ensure your supplier is applying the correct regional rates and TCR band, and we handle any disputes on your behalf.
Act Today
The April 2026 changes and significant, and for many businesses, unexpected. A quick review now can prevent budget shock later.
If you want to confirm whether your site is in the right capacity band or understand how the April reset will affect your bill, our team is here to help – and the first step is completely free.
Book Your Free Utility Health Check here.
