SSE PLC

Regulatory Filings • Dec 4, 2025

National Storage Mechanism | Additional information

RNS Number : 2460K

SSE PLC

04 December 2025

SSEN Transmission responds to Ofgem's RIIO-T3 Final Determination

SSEN Transmission notes the publication of Ofgem's Final Determination for the RIIO-T3 price control period, which comes at a critical time for securing clean, affordable power for families and businesses across the country.

The investment it delivers will help reduce reliance on imported energy from overseas, remove grid bottlenecks and strengthen energy security, as well as acting as a major catalyst for economic growth, jobs and supply chain investments across the UK to unlock the country's full potential.

Based on an initial assessment, SSEN Transmission welcomes improvements to baseline total expenditure and notes the updates to Ofgem's proposed financial parameters and incentive regime. However, a detailed assessment is required to determine the overall investability of the package.

With more material to be released by Ofgem over the next few days, SSEN Transmission will review and assess the price control package in its entirety over the coming weeks, including the proposed licence changes due to be consulted upon shortly.

SSEN Transmission remains committed to constructive engagement with Ofgem to secure an investible, financeable and ambitious price control settlement which underpins the unprecedented levels of investment required to deliver clean power, energy security and lower bills for current and future generations.

Notes

·    The RIIO-T3 Price Control period runs from April 2026 - March 2031 and is part of Ofgem's regulatory framework aimed at ensuring energy network companies have enough revenue to invest in maintaining and improving their networks.

SSEN Transmission's dedicated Business Plan website:

www.ssen-transmission.co.uk/RIIO-T3

About SSEN Transmission

·    Headquartered in Perth - with offices in Aberdeen, Inverness and Glasgow - SSEN Transmission is responsible for the electricity transmission network in the north of Scotland, investing in and maintaining the high voltage 132kV, 220kV, 275kV and 400kV electricity transmission network.

·    SSEN Transmission's strategic objective is to enable the transition to a low carbon economy, helping to secure the country's clean power and energy security ambitions. It does this by building the electricity transmission network infrastructure required to connect and transport renewable electricity in the north of Scotland to the towns, villages and cities where it's needed, as it delivers a network for net zero emissions.

·    SSEN Transmission is owned 75% by SSE plc and 25% by Ontario Teachers' Pension Plan Board (Ontario Teachers').

·    Learn more about SSEN Transmission by visiting www.ssen-transmission.co.uk, X, LinkedIn or Instagram.

Enquiries
Investors	SSE Investor Relations	[email protected]	Michael Livingston	+44 (0)345 0760 530
Media	SSE Media	[email protected]	Greg Clarke	+44 (0)345 0760 530

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