As the UK continues its journey toward a low-carbon future, new measures are being introduced to support investment in sustainable and secure energy generation. One of the latest developments is the Nuclear Regulated Asset Base (RAB) Levy, which will soon appear on business electricity bills.

While any new charge can raise questions, it’s important to understand why it’s being introduced, how it will be applied, and what the financial impact might be for your organisation.

What Is the Nuclear RAB Levy?

The Nuclear RAB Levy is a government-backed mechanism designed to help fund the construction and long-term operation of new nuclear power projects in the UK, most notably Sizewell C.

Historically, nuclear projects have required huge upfront capital and decades-long repayment periods, making them difficult to finance. The RAB model changes this by allowing investors to start recovering costs during construction, spreading the financial burden across bill payers through a small levy on electricity consumption.

In short, this approach aims to make nuclear energy projects more affordable and financially sustainable, while maintaining transparency and accountability through Ofgem’s oversight.

Why Is the Levy Being Introduced?

The UK government considers nuclear power a vital part of its plan to reach net-zero carbon emissions by 2050. It provides a stable, low-carbon baseload supply that complements variable renewable energy sources such as wind and solar.

By introducing the RAB model, the government aims to attract private investment in new nuclear capacity, reduce reliance on imported fossil fuels, and support long-term energy price stability for UK consumers and businesses.

How Will the Nuclear RAB Levy Be Applied?

The levy will appear as a separate line item on electricity bills, similar to existing environmental or policy-related charges. It will be collected by suppliers and transferred to the Low Carbon Contracts Company (LCCC), which manages the scheme.

Key points:

Applies to electricity only – gas bills are unaffected.
Usage-based – larger energy consumers will contribute proportionally more.
Phased introduction – begins in late 2025, with quarterly rate reviews by Ofgem and the LCCC.
Collected by energy suppliers – and reconciled periodically to ensure transparency.

When Will It Start and What Are the Actual Rates?

According to the LCCC and the Department for Energy Security and Net Zero (DESNZ), the first Nuclear RAB Levy rates have been confirmed for Q4 2025.

Levy Type	Effective Dates	Rate
Operational Costs Levy (OCL)	1 Oct 2025 – 31 Dec 2025	£0.0028 / MWh
Interim Levy Rate (ILR)	1 Nov 2025 – 30 Nov 2025	£3.455 / MWh
Adjusted ILR	1 Dec 2025 – 31 Dec 2025	£3.540 / MWh

From October 2025, no RAB levy will apply for the first month. Charges will begin appearing on bills from November 2025 onwards. The LCCC will publish updated ILR and TRA values 30 days before each quarter, allowing suppliers to plan and bill accurately.

Forecast Costs for Businesses

Although any new charge attracts attention, the Nuclear RAB Levy is designed to be modest in impact:

For small-to-medium businesses, the initial cost is expected to add around £10–£25 per year based on typical consumption (50,000–100,000 kWh annually).
For larger commercial and industrial users, the cost will scale with consumption but is still likely to represent less than 1% of total electricity spend.
Future LCCC forecasts suggest rates of £3.50–£4.50 per MWh through to 2027, varying slightly by season.

Importantly, these charges remain minor compared to fluctuations in wholesale electricity prices, meaning their effect on total bills should be limited.

Are Any Businesses Exempt?

Some sectors may qualify for partial or full exemption under the Energy Intensive Industries (EII) scheme. Eligible businesses—such as those in chemicals, metals, paper, or ceramics—should continue to apply through DESNZ’s established EII process to ensure exemptions are reflected in their billing.

The Bigger Picture: Building a Stable, Low-Carbon Energy Future

The Nuclear RAB Levy is a small but significant step toward ensuring the UK’s long-term energy resilience. By contributing to the financing of Sizewell C and future nuclear projects, businesses are helping to stabilise the UK’s power supply, reduce dependence on volatile global energy markets, and support the national transition to net-zero by 2050.

While the levy introduces a slight additional cost, its purpose is to deliver greater price predictability and energy security in the years ahead.

What Should Businesses Do Next?

There’s no immediate action required, the levy will be automatically applied by suppliers once it takes effect. However, businesses should:

Review energy budgets for 2025/26 to account for a small additional charge.
Stay informed of quarterly rate updates published by the LCCC.
Explore energy-efficiency or consumption-reduction measures to offset the impact.

At eyebright, we’ll continue to monitor developments and provide our clients with clear, timely updates to help manage costs and plan ahead with confidence.