If you’ve noticed a change in your business electricity bill recently, you’re not alone. From April 2026, Transmission Network Use of System (TNUoS) charges have been updated across the UK – and for many business owners, it’s the first time they’ve had to think about what these charges actually are and why they exist.
The good news? They’re not as complicated as they sound. Here’s everything you need to know about TNUoS.
What Is TNUoS?
TNUoS (Transmission Network Use of System) are charges set by the National Grid ESO (Electricity System Operator) to cover the cost of transporting electricity across the
UK’s high-voltage transmission network. This is the infrastructure that moves electricity from where it’s generated to where it’s needed. These TNUoS charges help to fund:
- Upgrades to ageing infrastructure: Much of the UK’s transmission network requires significant ongoing investment to modernise.
- Connection of new renewable energy sources: As the UK transitions to cleaner energy, the grid needs to expand to accommodate new generation sites.
- Ongoing reliability and resilience: Constant balancing of supply and demand across the country.
- System balancing: Managing the flow of electricity across the network in real time.
Whilst these charges are unavoidable, understanding them is the first step to managing their impact on your business.
Why are TNUoS charges increasing in 2026?
TNUoS charges are rising across the UK, and the primary driver is the scale of investment required to modernise the electricity system.
The UK’s transition to renewable energy is accelerating. Wind farms, solar installations, and other clean energy sources are increasingly distributed across the country, often in remote locations outside of population centres. Connecting these sources to the grid requires significant new infrastructure, and that comes at a cost that is shared across all electricity users.
At the same time, demand for electricity is growing. The electrification of transport, heating, and industry means the national grid is under more pressure than ever before. TNUoS charges reflect the investment needed to keep pace with that demand, both now and in the years ahead.
For businesses, this means the network charge portion of your electricity bill is likely higher than it was previously – and awareness of what’s driving that increase is increasingly important for budgeting and planning ahead.
How are TNUoS charges calculated?
TNUoS charges aren’t a single flat fee – there are two distinct components that make up what you pay:
- Locational Charge: This is based on your electricity consumption and where your business is located on the network. Businesses in areas further from major generation sources, or that place greater strain on the local transmission network, may pay more. This element of TNUoS is designed to reflect the actual cost of transporting electricity to your location.
- Non-Locational (Residual) Charge: This is a fixed daily charge, calculated as a £/day rate that varies depending on your meter type. Unlike the locational element, this doesn’t change based on where you are – it’s a baseline contribution towards the shared cost of the network.
TNUoS typically accounts for around 7% of a business’s total electricity cost, though this can vary depending on the type of connection your business has. Businesses with higher voltage connections may see a proportionally greater impact.
Who pays for TNUoS charges?
TNUoS charges apply to electricity consumers across the UK, collected by your supplier and passed directly through to your bill – meaning they sit outside of your supplier’s control, and outside of most fixed-price protections.
Fixed-rate contracts are designed to protect you from fluctuations in the wholesale cost of energy – but TNUoS charges are a pass-through cost, which means they can still apply even within a fixed-price agreement. The terms vary depending on your contract, so if you’re unsure how your arrangement handles network charge changes, it’s worth checking with your supplier directly.
What Does This Mean for Your Business?
For most businesses, the practical impact is straightforward. Your electricity bills are likely to be higher than they were before April 2026, with the TNUoS element contributing to that increase.
The businesses most likely to feel the change most acutely are those with:
- Higher electricity consumption: More usage means a larger locational charge exposure.
- Higher voltage connections: These can carry a greater TNUoS weighting.
- Energy-intensive operations: Where electricity represents a significant proportion of overall operating costs.
For businesses with tighter margins or less flexibility in their energy spend, understanding the breakdown of your bill is more important than ever so you can plan ahead accordingly.
Is there anything your business can do?
TNUoS charges are unavoidable. Every electricity user in the UK contributes to the cost of the transmission network – however, there are steps businesses can take to manage their exposure:
- Review your contract terms: Understand how network charge changes are handled within your current agreement.
- Monitor your consumption: The locational element of TNUoS is tied to usage, so energy efficiency measures such as solar panel and battery storage can have a direct impact.
- Speak to your supplier: If you’re unsure about how these charges affect your specific bill or contract, getting clarity early is always worthwhile.
Understanding TNUoS charges is just the start. The more informed you are, the better placed you’ll be to make decisions that protect your bottom line.
Could commercial solar and battery storage help reduce your exposure to TNUoS?
Whilst these charges are inevitable, businesses that generate their own electricity on-site can meaningfully reduce their reliance on the grid and exposure to rising network costs.
Commercial solar panels, particularly when paired with battery storage, allow businesses to:
- Generate electricity during daylight hours: Reducing the volume of energy drawn from the transmission network during peak periods.
- Store surplus energy for later use: Battery storage means solar generation doesn’t go to waste when demand is low, giving businesses access to self-generated power throughout the day.
- Reduce overall grid consumption: The less electricity your business draws from the network, the lower your exposure to the usage-based elements of network charges like TNUoS.
The locational element of TNUoS is directly tied to consumption, so any reduction in grid draw has an impact on that portion of your bill. For energy-intensive businesses, or those with higher voltage connections already feeling the weight of the April 2026 changes, this can represent a meaningful long-term saving.
Beyond the TNUoS angle, commercial solar and storage also provide a broader hedge against energy price volatility – giving businesses greater control over their operating costs at a time when the wider energy market remains unpredictable due to ongoing geopolitical conflict.
Find out more about solar for your business.
Speak to the Utilita Business Team
Have you got a question about TNUoS charges or how they’re affecting your business energy costs? Our team is here to help. Get in touch and we’ll talk you through what it means for you.