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RIIO-3 Final Determinations: Electricity Transmission, Gas Distribution and Gas Transmission sectors

Ofgem's Final Determinations (published 4 December 2025) for the 2026–2031 network price controls, unlocking £28 billion of investment in electricity transmission grid capacity — the foundational investment plan for the grid infrastructure that AI Growth Zones will rely on.

▤ Verbatim text from source document

RIIO-3 Final Determinations for the Electricity Transmission, Gas Distribution and Gas Transmission sectors | Ofgem

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RIIO-3 Final Determinations for the Electricity Transmission, Gas Distribution and Gas Transmission sectors

Publication type:

Decision

Publication date:

4 December 2025

Topic:

Energy network price controls,

Electricity transmission,

Gas transmission,

Gas distribution

Decision for:

RIIO-3 Draft Determinations for the Electricity Transmission, Gas Distribution and Gas Transmission sectors

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Related links

Modifications to the RIIO-3 licences and associated documents

RIIO-3 Draft Determinations for the Electricity Transmission, Gas Distribution and Gas Transmission sectors

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Our Final Determination decisions for the network price controls between 1 April 2026 and 31 March 2031 (RIIO-3).

RIIO (Revenues = Incentives + Innovation + Outputs) is our framework to ensure that the monopoly companies operating our gas and electricity networks have sufficient revenue to invest in and run their networks, and deliver what customers value.

The current electricity and gas transmission and gas distribution price controls (known as RIIO-2) end on 31 March 2026. The next price control (RIIO-3) will run for five years, from 1 April 2026 to 31 March 2031. Following our review of the responses to our RIIO-3 Draft Determinations consultation, we are now publishing our Final Determinations for RIIO-3.

Notesome of the RIIO-3 Final Determinations financial model Excel files attached below are not fully accessible. If you require an alternative format, please contact
RIIO3@ofgem.gov.uk
.

Main document

RIIO-3 Final Determinationsoverview document [PDF, 4.76MB]

Errata tracker - RIIO-3 Final Determinations [XLSX, 59.05KB]

Subsidiary documents

RIIO-3 Final Determinationselectricity transmission [PDF, 2.17MB]

RIIO-3 Final Determinationsgas distribution [PDF, 2.60MB]

RIIO-3 Final DeterminationsNational Gas Transmission [PDF, 1.09MB]

RIIO-3 Final DeterminationsNational Grid Electricity Transmission (NGET) [PDF, 626.30KB]

RIIO-3 Final DeterminationsScottish Hydro Electric Transmission (SHET) [PDF, 409.20KB]

RIIO-3 Final DeterminationsScottish Power Transmission (SPT) [PDF, 297.63KB]

RIIO-3 Final DeterminationsCadent [PDF, 669.17KB]

RIIO-3 Final DeterminationsNorthern Gas Networks (NGN) [PDF, 374.35KB]

RIIO-3 Final DeterminationsSGN [PDF, 651.97KB]

RIIO-3 Final DeterminationsWales and West Utilities (WWU) [PDF, 491.54KB]

RIIO-3 Final Determinationsfinance annex [PDF, 1.36MB]

RIIO-3 Final Determinationsimpact assessment [PDF, 753.76KB]

Second independent report on ongoing efficiency [PDF, 941.67KB]

RIIO-3 Final Determinations Gas Transmission Business Plan Financial Model [XLSM, 13.63MB]

RIIO-3 Final Determinations Electricity Transmission Business Plan Financial Model [XLSM, 13.69MB]

RIIO-3 Final Determinations Gas Distribution Business Plan Financial Model [XLSM, 16.65MB]

RIIO-3 Final Determinations Cost of Debt model [XLSM, 25.71MB]

RIIO-3 Final Determinations WACC rates model [XLSX, 7.64MB]

Print this page

Related links

Modifications to the RIIO-3 licences and associated documents

RIIO-3 Draft Determinations for the Electricity Transmission, Gas Distribution and Gas Transmission sectors

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