UK Launches RFAS Aviation Scheme to Verify SAF Claims

A new framework designed to provide independent verification for Sustainable Aviation Fuel (SAF) claims has been launched in the United Kingdom. The initiative, named RFAS Aviation, was developed by the Zemo Partnership to create a standardized and auditable process for tracing SAF from production to deployment, directly supporting airlines' compliance with emissions reduction targets.

This scheme is a critical development for UK-based airline operators, as it provides the necessary infrastructure to substantiate claims for Greenhouse Gas (GHG) reductions under the United Kingdom Emissions Trading Scheme (UK ETS). By ensuring a robust chain-of-custody for SAF, RFAS Aviation enables airlines to reliably account for the use of lower-carbon fuels, which is essential for meeting national decarbonization goals. The first fuel supplier to achieve verification under the new framework is Valero Energy Limited.

Regulatory Framework and Mandates

The RFAS Aviation scheme operates within two key UK regulatory structures: the UK ETS and the UK SAF Mandate. Under the UK ETS, a cap-and-trade system, airlines are required to surrender allowances for their carbon emissions. According to the UK ETS Authority, eligible SAF that meets minimum GHG reduction thresholds is zero-rated, meaning it is treated as if it produces zero emissions. The verification provided by RFAS Aviation gives regulators confidence that the SAF used is traceable and meets sustainability criteria, allowing airlines to reduce their allowance surrender obligations and lower compliance costs.

This verification system is increasingly important due to the UK SAF Mandate, which came into force on January 1, 2025. The mandate, established by the UK Department for Transport, legally requires aviation fuel suppliers to blend an increasing amount of SAF into the national fuel pool. The initial requirement is for SAF to constitute 2% of the total supply, with targets set to increase to 10% by 2030 and 22% by 2040. This escalating requirement drives demand for SAF and necessitates a trusted verification system to prevent fraud and ensure genuine emissions reductions.

How RFAS Aviation Works

RFAS Aviation is an extension of the existing Renewable Fuels Assurance Scheme (RFAS), which has been successfully used in the UK's road transport sector for years. The Zemo Partnership adapted this proven model for the unique requirements of the aviation industry. A central component of the new scheme is a standardized SAF Declaration, which aligns reporting requirements with the UK ETS and the Environment Agency's rules.

This declaration serves as a formal record that bridges the gap between the physical blending of SAF with conventional jet fuel and the complex world of regulatory emissions reporting. According to Gloria Esposito, Director of Sustainable Business at the Zemo Partnership, the scheme provides the independent verification needed to give airlines, suppliers, and regulators confidence in the traceability and sustainability of SAF. She highlighted that close collaboration with the Environment Agency ensures the framework is fully aligned with UK ETS compliance needs.

Industry Impact and Stakeholders

The introduction of the RFAS Aviation scheme has significant impacts on several key stakeholders:

• UK Airline Operators: Airlines are the primary beneficiaries, gaining a standardized, auditable document to reliably claim the zero-rating for SAF. This simplifies UK ETS compliance and reduces the financial burden of purchasing emissions allowances.
• Aviation Fuel Suppliers: Suppliers like Valero Energy Limited must now adhere to the RFAS Aviation audit and assurance processes. This requires them to substantiate sustainability claims to their airline customers, adding a layer of due diligence but also providing a competitive advantage for those who achieve certification.
• UK Environment Agency: As the regulator, the Environment Agency benefits from streamlined, standardized reporting. Independent verification reduces the administrative burden of auditing individual SAF claims, allowing for more efficient oversight of the UK ETS.

Context and Precedents

This initiative follows a well-established pattern of creating assurance frameworks for renewable fuels in the UK. The launch of assurance schemes under the Renewable Transport Fuel Obligation (RTFO) in 2008 provided the direct regulatory and operational template that RFAS Aviation builds upon. That system established a robust verification process for biofuels in road transport, proving the model's effectiveness.

Globally, the push for SAF verification is not new. The ICAO's implementation of the CORSIA Eligible Fuels (CEF) framework between 2019 and 2021 established international sustainability criteria for SAF. The RFAS Aviation scheme can be seen as the UK's localization of these global efforts, tailoring them specifically for its domestic emissions trading system.

What Comes Next

The launch of RFAS Aviation is a foundational step in a long-term regulatory timeline. Looking ahead, the aviation industry faces several key milestones. A significant change will occur in 2026, when the UK ETS Authority is set to end the free allocation of aviation emissions allowances, increasing the financial incentive for airlines to use verified SAF.

Further into the future, the UK SAF Mandate will continue to drive the market, with the blend requirement rising to 10% by 2030 and 22% by 2040. The RFAS Aviation scheme will be essential for tracking and verifying the growing volumes of SAF required to meet these legally binding targets.

Why This Matters

For the UK aviation industry, the RFAS Aviation scheme is more than just a new compliance tool; it is a critical piece of infrastructure for decarbonization. It establishes a trusted and transparent market for sustainable fuels, providing the confidence needed for airlines to invest in SAF and for suppliers to scale production. This framework is fundamental to ensuring the integrity of the UK's strategy to reduce aviation emissions and meet its net-zero commitments.