From 1 October 2025, the UK’s electricity balancing charge—known as the Balancing Services Use of System (BSUoS)—will rise significantly, with the tariff increasing from £10.74/MWh (1.074 p/kWh) to £15.69/MWh (1.569 p/kWh). The new rate will remain in place until 31 March 2026.

This 46% increase will have a direct impact on businesses with pass-through energy contracts, as BSUoS costs are itemised separately on invoices and passed directly to end-users. For companies with substantial electricity consumption, the change will represent a noticeable uplift in costs.

What is BSUoS?

BSUoS stands for Balancing Services Use of System. It is a charge set by the UK’s National Energy System Operator (NESO) to recover the cost of keeping the electricity grid stable and secure. These costs cover activities such as:

• Adjusting generation when demand suddenly changes
• Managing supply during periods of constraint
• Maintaining system frequency and reliability

Since April 2023, BSUoS has been recovered from final demand users through their suppliers. For businesses on pass-through contracts, this means the charge is shown transparently as a line item on invoices and fluctuates in line with NESO’s six-monthly tariff updates.

The October 2025 Increase

The next tariff change (Fixed Tariff 6) will see BSUoS rise by nearly half compared to the April–September 2025 level. For illustration:

Period BSUoS Rate (p/kWh) Consumption (kWh) BSUoS Cost   Change

Apr–Sep 2025                      1.074                                          1,400,000                                    £15,036                                —

Oct–Mar 2026                      1.569                                          1,400,000                                     £21,966                         +£6,930

For a business consuming 1.4 GWh over six months, this represents a cost increase of nearly £7,000 purely from BSUoS charges.

Why the BSUoS Increase Matters for Corporate Buyers

For organisations managing large or multi-site portfolios, the upcoming rise underscores the importance of understanding the components of pass-through contracts. While these contracts provide transparency and can offer cost advantages when markets fall, they also expose businesses directly to changes in regulated charges such as BSUoS.

Key considerations include:

• Budget certainty: Forecasting for April 2025–March 2026 should include higher BSUoS costs.
• Procurement strategy: Weighing the pros and cons of fixed vs pass-through contracts depending on appetite for risk and transparency.
• Efficiency focus: Reducing overall consumption can help mitigate the impact of rising non-commodity costs like BSUoS.

Looking Ahead: Forecasted BSUoS Rates for 2026

The October 2025 increase is part of the UK’s evolving energy cost landscape, with balancing costs expected to remain under pressure as the grid transitions to higher levels of renewables and flexibility services. NESO sets BSUoS tariffs twice a year, meaning further adjustments can be expected from April 2026. We will continue to keep you updated but at present, the forecasted rates for April 2026 - October-2026 are:

April 2026 to September 2026 – 1.455 p/kWh

October 2026 to March 2027 – 1.103 p/kWh

For corporate buyers, understanding these changes - and building them into procurement and risk management strategies - is essential to staying in control of energy budgets.

References

https://www.neso.energy/industry-information/charging/balancing-services-use-system-bsuos-charges?

Article by Neil Fraser