Brace for impact: Third‑party charges and TNUoS set to climb in April
As we move into the next energy‑pricing period, many businesses will see a sharp increase in non‑commodity or “third‑party” energy charges. Among these, the transmission network charge known as TNUoS is likely to dominate the cost rise. Here’s what you need to know - and how to prepare.
What are we talking about?
“Third‑party charges” (also called non‑commodity costs or non‑energy costs) cover all the charges that sit on top of the basic electricity unit rate. These typically include:
Network charges (transmission, distribution)
System balancing and capacity costs
Environmental and renewable support costs
TNUoS (Transmission Network Use of System) is the charge that helps pay for the high‑voltage transmission network: maintaining, upgrading, and reinforcing the wires and infrastructure that carry electricity from generation to distribution networks.
What’s changing - and when
From 1 April 2026, substantial uplifts in TNUoS standing charges are expected for business electricity users.
Some highlights of the change:
The “demand‑residual” component (the fixed £/site/day element) is forecast to nearly double for many meter bands in 2026/27.
Forecasts show total TNUoS revenue rising from ~£8.9 billion in 2026/27 toward ~£13.6 billion by 2030/31 under the new regulatory period.
For example: a site in one band might see an increase of £3.37 per day for its meter band. Over a year, that adds up.
Another piece of the puzzle: third‑party costs overall (beyond just TNUoS) have been steadily rising for years - inflation, network investment, decarbonisation, shrinking demand are all drivers.
Why is this happening?
Several intertwined reasons:
The UK electricity grid is undergoing a major transition: more renewables, more flexible generation, more reinforcement of the transmission network. To fund this, higher charges are needed.
The regulatory regime (for example RIIO‑ET3) sets the allowed revenues for network operators, and the latest business plans are pointing to increased investment and costs.
Because fixed standing charges are charged per site/meter rather than per kWh, some of the increases hit even if consumption remains flat.
What about fixed contracts?
Even if you’re on a fixed-price electricity contract, you may not be completely insulated from these changes. Many contracts treat third-party charges - including TNUoS, distribution, and system charges - as pass-through costs. This means your unit rate for energy might stay the same, but your bill could still rise to reflect higher network and regulatory charges. It’s worth checking your contract terms to understand exactly which costs are included in your fixed price and which are passed through, so you can avoid surprises when the new tariffs take effect in April.
What this means for you
If you’re managing or budgeting energy costs for your business (or organisation), here are the practical implications:
Your standing charge (the fixed £/day meter cost) is likely going up - regardless of how much electricity you use. Even if your unit rate stays the same.
If your contract runs beyond April 2026 and includes pass‑through of third‑party charges (which many do) then you may see increases mid‑contract.
For smaller sites or businesses, the per‑meter increase might be less dramatic than for large industrial users, but it still warrants attention.
Budgeting: if you’ve planned energy costs on the assumption that standing charges remain stable, you may now need to revise upward.
Consider whether your procurement strategy (contract term, fixed vs pass‑through, meter banding) still makes sense under these new cost pressures.
What you can do to prepare / mitigate
Here are some proactive steps:
Check your contract - see whether third‑party charges (including TNUoS) are fixed or pass‑through. If they’re pass‑through, you’re exposed.
Know your meter band / site type - the increase will vary by band and location (meter type, voltage, region) so understand where you sit.
Budget for the impact -estimate the likely increase (use published forecasts) and adjust your forward cost models accordingly.
Explore reducing exposure - while the standing charge portion is fixed per meter, you can focus on:
Ensuring you’re in the correct meter band / voltage level (avoiding being in too high a band)
Evaluating whether contract end dates or renewal terms can align with the tariff change
Investigating energy‑efficiency, demand‑management, onsite generation/storage to reduce unit rate spend and offset cost increases.
Stay informed - final tariff figures for the new period are published only a few months ahead of the start. Monitor announcements from your supplier, the regulator, and network operator.
Key dates to remember
Draft tariffs for 2026/27: usually published around November 2025.
This will give us the first indication of what the increased charges will look like for each meter.
Final tariffs locked in by 31 January 2026.
This is the definitive standing charge rate you'll pay from April 2026
New tariffs go live: 1 April 2026.
This is when they take effect and you will the see the increase in your bills.
Final thought
The upcoming step‑change in TNUoS and other third‑party (non‑commodity) charges is arguably one of the less visible but very meaningful cost pressures for many businesses. While your unit rate remains important, in this new environment, standing charges and fixed network costs need to be given much greater attention.
You may not be able to avoid all of the increase (the network costs have to be passed through somewhere), but you can reduce surprises - by understanding your contract, budgeting early, and exploring where you have control.
We’re here to help you navigate these changes, so please get in touch if you have questions or need guidance, and feel free to recommend us to any business that could benefit from our expertise.