For years, most commercial energy strategies have focused on wholesale price timing, consumption reduction, and supplier negotiation. Those still matter, but they no longer tell the full story.
A major cost shift is now coming from the infrastructure behind the electricity system itself. Transmission Network Use of System charges, known as TNUoS, recover the cost of installing and maintaining the electricity transmission network across England, Wales, Scotland, and offshore. NESO confirms that tariffs are based on geographical charging zones and are published annually by 31 January, taking effect from 1 April each year.
For multi-site businesses, the key issue is simple: rising network costs are increasingly fixed, regional, and contractual. That means standard energy-saving measures alone may not protect budgets.
Why Infrastructure Costs Are Now a Board-Level Issue
The UK is investing heavily in electricity transmission infrastructure as part of the next network price control period. Ofgem’s RIIO-3 framework runs from 1 April 2026 to 31 March 2031 and sets the revenue framework for monopoly gas and electricity network operators.
That investment has a direct commercial consequence. The benchmark data highlights a sharp TNUoS demand residual movement, from around £3.84 billion to £7.52 billion, a £3.68 billion uplift and a 94 percent increase in the cost recovery pot. SmartestEnergy also reported the same £7.52 billion 2026/27 forecast and the £3.68 billion increase compared with 2025/26 final tariffs.
Even where later tariff forecasts have moved, the direction of travel remains clear. NESO’s draft tariff update still forecast total TNUoS revenue at £7.65 billion for 2026/27 and demand revenue at £6.43 billion.
The Problem With Calling It an Energy Saving Challenge
Many businesses will instinctively respond to rising electricity costs by focusing on consumption reduction. That is sensible, but it does not solve this problem on its own.
A large part of this increase is being loaded into fixed residual standing charges. These are daily charges applied to sites and meters, rather than costs that can be fully avoided by reducing kWh consumption. NESO’s tariff material shows demand residual charges are impacted by demand revenue, charging band allocation, and site counts, with charges expressed through £ per day residual structures.
That changes the question for finance teams.
The question is no longer, “How do we use less energy?”
The better question is, “Which of our sites are exposed to fixed infrastructure cost increases, and which contract terms allow those increases to reach our invoices?”
Multi-Site Businesses Are More Exposed
A single-site business may see the increase as one extra line item. A multi-site operator sees something more complex.
Every site sits in a location. Every location sits in a charging zone. Every meter has a profile, voltage level, banding, and supplier treatment. When multiplied across a national estate, small differences become material.
The benchmark summary shows TNUoS alone expanding from around 8 percent of a standard half-hourly electricity bill to more than 13 percent, with energy-heavy locations potentially seeing TNUoS represent up to 25 percent of the total bill.
The businesses most exposed are often those with:
The Regional Location Trap
TNUoS is not evenly distributed. NESO states that supplier tariffs are based on actual demand and the geographical zone users are connected to.
That matters because two sites using similar amounts of electricity can face very different infrastructure costs simply because they are in different parts of the country.
The benchmark summary flags South Wales, South West England, and South East England as areas where multi-site footprints may be hit harder by regional tariff effects. External market commentary has also identified the South West, South East, London, and South Wales as areas with notable increases or higher tariff exposure.
For national operators, this creates a hidden exposure inside the estate. It is not enough to know the total annual electricity spend. Businesses need to know which locations are carrying the highest infrastructure risk.
The Fixed Contract Blind Spot
Many commercial operators believe a fixed energy contract protects them from market movement. That may be true for wholesale energy. It is not always true for non-commodity costs.
Pass-through costs usually cover charges linked to transporting and distributing energy, balancing the system, and funding government or industry schemes. Supplier guidance explains that these costs are generally managed by third parties, government, or Ofgem, rather than controlled by the supplier.
This creates a serious blind spot. A contract may look fixed at headline level, while still allowing network charges, policy charges, or third-party charges to be passed through during the term.
For 2026 and beyond, that distinction matters.
A business may have a fixed rate and still face a budget shock if its contract contains pass-through language that allows infrastructure cost increases to be recovered directly through invoices.
What Businesses Should Do Now
The immediate priority is not to panic or renegotiate blindly. It is to map the risk.
A proper review should answer four questions:
Which sites are in the highest TNUoS charging zones?
Which meters are exposed to fixed residual standing charge increases?
Which contracts include pass-through clauses for network and third-party charges?
Which supplier invoices already show evidence of unrecovered or newly passed-through infrastructure costs?
This is where procurement, finance, and energy teams need to work from the same evidence. Site lists, meter data, regional bands, contract clauses, and invoice lines should be reviewed together, not separately.
Nationwide Utilities View
The next phase of energy cost control will not be won by watching wholesale prices alone.
The businesses that protect their budgets will be the ones that understand the difference between energy price risk and infrastructure charge risk. One is driven by the market. The other is driven by regulated network cost recovery, regional location, and contract wording.
That is why multi-site businesses should treat TNUoS exposure as a strategic finance issue, not just an energy line item.
A fixed contract may still carry variable risk.
A lower consumption site may still carry a higher standing charge.
A national estate may hide regional cost pressure until the invoice arrives.
The businesses that act early will have a clearer view of where the exposure sits, which sites are most affected, and which contract clauses need attention before the next renewal.
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