If you’ve spent any time on LinkedIn lately, you’ll have seen it. TNUoS charges are rising sharply from April 2026, and for many businesses the increase will be significant.
The National Energy System Operator (NESO) has confirmed final Transmission Network Use of System (TNUoS) tariffs for 2026/27, and while they’re almost identical to the draft figures, they are substantially higher than the current year. For most power consumers, residual charges alone will rise by between 28% and 116%, with a volume-weighted average increase of around 64% year on year.
That’s not a marginal adjustment. It’s a structural shift in network costs.
So, what does this mean for your business, and how can you avoid unexpected increases landing on your invoice?
A quick recap: what is TNUoS?
TNUoS charges fund the UK’s high-voltage electricity transmission network. This is the infrastructure that moves power from generators, including offshore wind and other renewable sources, to local distribution networks.
They typically account for 5–10% of your total electricity costs and sit within the non-commodity element of your bill.
There are two main components:
- Residual charges – fixed standing charges, usually applied as £/site/day, recovering the bulk of network costs.
- Locational demand charges – variable charges depending on where your site is located and how much strain it places on the network.
From April 2026, residual charges will form over 90% of total TNUoS costs for most consumers. And this is where the steep increases are happening.
NESO forecasts TNUoS revenues rising to around £8.9 billion in 2026/27. That uplift is being passed through to users of the system.
Why are costs increasing so sharply?
The short answer: grid transformation.
April 2026 marks the start of Ofgem’s RIIO-ET3 (Revenue = Incentives + Innovation + Outputs), the new five-year electricity transmission price control. To deliver Clean Power 2030 and connect large volumes of remote renewable generation (especially offshore wind), the transmission network needs major reinforcement.
That includes:
- Upgrading transmission lines
- Building new infrastructure
- Strengthening the grid to handle decentralised generation
These upgrades are essential for decarbonisation and security of supply. But they come at a cost.
On top of that, updated Targeted Charging Review (TCR) banding thresholds from April 2026 will move many sites into higher residual charging bands. For some businesses, this means a step change in fixed daily charges regardless of usage.
What this means for your electricity contract
The impact on your business depends largely on contract structure.
If you are on a pass-through contract, the new TNUoS charges will flow directly onto your invoice from April.
If you are on a fixed contract, the situation depends on how network costs were forecast and built into your agreement. Under-forecast allowances could still create exposure.
Location, voltage level, and banding, will also influence the outcome.
In short, April 2026 is not a business-as-usual adjustment.
The high-benefit alternative: YouFix includes TNUoS in the price
As a result of these changes, at Crown Gas & Power, we believe cost certainty matters more than ever.
That’s why with our YouFix electricity product, TNUoS charges are included within your fixed price.
There are no separate residual surprises.
No unexpected standing charge uplifts mid-contract.
No need to model multiple TNUoS scenarios into your budgets.
You agree your unit rate, your standing charge, and your contract length upfront. That price remains fixed for the duration of your agreement.
In a year where residual charges alone are increasing by an average of 64%, that stability is important.
What that gives your business:
Budget certainty: You can forecast energy costs accurately without second-guessing network changes.
Risk protection: Rising transmission charges don’t suddenly erode your margins.
Simplicity: Clear, transparent pricing without complex pass-through calculations.
Multi-site consistency: Whether you operate one site or many, you avoid site-by-site exposure to banding changes.
For energy-intensive sectors such as manufacturing, logistics, and data centres, this removes a significant layer of volatility. But the benefit is just as real for smaller businesses, where even modest standing charge increases can hit operating costs hard.
Residual banding changes: don’t get caught out
From 1 April 2026, residual charging bands are changing. Many businesses will move bands without realising it until invoices arrive.
If you are reviewing renewal options now, it’s critical to understand:
- Your current banding
- Your new banding from April
- The projected five-year impact under RIIO-ET3
If you prefer to remove that uncertainty altogether, a fixed product that incorporates TNUoS within the agreed price provides clarity from day one.
Preparing for 2027 and beyond.
NESO will publish its initial 2027/28 forecast in April 2026. Current projections suggest elevated network investment will continue through to 2030.
This isn’t a one-year spike. It’s a structural shift in how the transmission network is funded.
Businesses that prioritise the following will be in a stronger position than those reacting after costs land:
- Contract review
- Cost modelling
- Scenario planning
- Fixed-price protection where appropriate
Stability in a changing market
The UK’s transition to a cleaner energy system is necessary. Grid upgrades are part of that journey.
But your business still needs cost control.
With YouFix electricity, TNUoS charges are built into your agreed price, helping you:
- Protect budgets
- Reduce exposure to network volatility
- Plan with confidence
TNUoS reform isn’t a short-term fluctuation. It reflects long-term structural investment in the UK’s grid, and that means elevated network costs are likely to remain part of the landscape for years to come.
Now is the time to understand your exposure, review your contract structure, and decide how much volatility you’re prepared to carry.
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