Business Electricity Costs in 2025–2026: New Energy Market Charges Explained

Several regulatory and market changes are on the horizon that will soon impact business electricity bills across the UK.

From late 2025, businesses could see additional levies added to their bills, with most organisations on fixed or pass-through contracts being impacted.

Understanding how these charges apply and what they might mean for your energy contract is key to staying prepared.

Transmission Network Use of System (TNUoS) Charges

The current electricity price controls (known as RIIO-2) end on 31st March 2026. The next price control, RIIO-3, will run for five years from 1st April 2026 to 31st March 2031.

Ofgem’s Draft Determination indicates a significant increase to these costs from April 2026. These charges fund the maintenance and development of the UK’s high-voltage electricity transmission network. Even businesses not directly connected to the high-voltage system will still see higher TNUoS costs.

Most suppliers will have now updated their forward prices to reflect these changes. If you’ve recently requested refreshed prices, this may explain an increase.

If you signed a fixed contract before 1st April 2026, some suppliers may still pass these costs on to you. However, if your contract is fully fixed, your prices will stay the same.

Nuclear Regulated Asset Base (RAB) Charges

Nuclear RAB charges are levies added to electricity bills to fund new UK nuclear projects, starting with the Sizewell C site which was introduced under the Nuclear Energy (Financing) Act 2022.

• For Energy Intensive Industries (EII), the scheme will significantly reduce costs, improving cash flow and competitiveness.

• For non-EII businesses, this will increase non-commodity costs on electricity bills.

  
  

The scheme will be implemented on 1st November 2025 and is estimated to cost around £3.50/MWh (0.35p/kWh), although final figures are yet to be confirmed.

Learn more via Ofgem – Nuclear RAB Model

Energy Intensive Industry (EII) Support Levy

The EII Support Levy (ESL) is a government-introduced charge to fund the Network Charging Compensation (NCC) scheme for Energy Intensive Industries (EII’s).

This mechanism supports businesses with high energy usage by offsetting some of their network charges.

However, the cost is passed on to electricity suppliers, who in turn pass it on to non-domestic customers outside the EII category.

• EII's will benefit from 60% relief on TNUoS, DUoS, and BSUoS charges.

• This support is expected to be backdated to April 2024.

• Businesses on fixed contracts may still see costs passed through depending on their supplier.

• Fully fixed contracts will remain unchanged.

For more details visit UK Government legislation on the EII Support Levy.

Market-Wide Half Hourly Settlement (MHHS)

The MHHS reform will impact all businesses currently on non-half-hourly (NHH) meters.

From October 2025, the industry will begin transitioning customers to MHHS, with full implementation by May 2027. This change will alter how electricity usage is measured, settled, and billed.

While much of the work will happen in the background, businesses may notice:

• Changes in billing and settlement.

• More detailed energy usage data.

• Potential extra charges for new half-hourly meters, depending on the supplier.

For more details visit PEP – MHHS and its impact on businesses

Need Advice?

Navigating these market changes can be complex. Our team is here to help businesses understand their bills, assess contract risks, and prepare for upcoming cost impacts.

Get in touch.

info@pepgb.com

0330 0022180