From 1 April 2026, many UK businesses may notice changes to their electricity standing charges.
In some cases, the increase may appear significant. However, the cause is not a supplier price rise, but a change to an industry-wide network charge known as Transmission Network Use of System (TNUoS).
Like many aspects of the UK energy market, the mechanics behind this change aren’t obvious. Understanding what’s happening can help businesses avoid unnecessary worry when notices arrive.
TNUoS charges are used to fund the construction, maintenance, and reinforcement of the UK’s high-voltage electricity transmission network.
These charges are set centrally by the National Energy System Operator (NESO) and approved by Ofgem. Electricity suppliers do not control the charge itself. They simply collect it through electricity bills and pass it through to the network.
The network upgrades being funded are substantial and include:
As the energy system evolves, the infrastructure supporting it must evolve as well.
The change will be introduced in April 2026 and relates to the residual element of TNUoS, which has been restructured by the regulator.
Historically, some transmission costs were recovered through electricity consumption. The reform moves more of these costs into fixed daily charges linked to the meter.
In practical terms, this means businesses may see:
This shift makes network cost recovery less dependent on how much electricity a business uses.
One of the more confusing aspects for businesses is that not all suppliers are implementing the change in the same way.
Some suppliers anticipated the reform and built the expected TNUoS costs into their contract pricing.
Others are applying the adjustment during the contract term through pass-through provisions contained in their supply agreements.
The end result is that some businesses are receiving notices of standing charge increases now, even though the underlying cost change affects the entire industry.
This can understandably feel like a surprise price increase, but in many cases it simply reflects when the supplier chose to incorporate the cost, not whether the cost exists.
A supplier applying a TNUoS adjustment during a contract does not necessarily mean the contract was more expensive overall.
In many cases, suppliers who embedded the expected costs earlier were already pricing them into higher contract rates.
This means that even where a business receives a TNUoS adjustment notice, the supplier they selected may still prove to have been the cheaper option overall compared with suppliers who priced these charges in from the outset.
For businesses that receive notifications referencing TNUoS or standing charge adjustments, the most practical step is to review the details with the supplier responsible for the contract. As with many aspects of energy billing, the precise financial impact will depend on how individual suppliers have incorporated these regulated network charges into their pricing structures.
