The UK’s first year under its Sustainable Aviation Fuel (SAF) mandate is already showing cracks. By mid-2025, SAF blending stood at just 1.29%, well short of the 2% target set for the year.
Unless uptake accelerates dramatically in the second half, the UK risks falling behind on one of its most visible decarbonization commitments.
What is at the root of this decrease? And how can the market turn production around?
When it comes to renewable fuels, the UK has long been recognized for its commitment to transparency.
Each year, the government releases five provisional Renewable Transport Fuel Obligation (RTFO) reports before publishing a final version. These reports don’t just track volumes. They go deeper, offering visibility into the 10 largest fuel suppliers and detailing exactly which fuels they are using.
The data covers fuel type, feedstock, country of origin, and carbon intensity, providing clarity across the industry and to the public. This openness is valuable for multiple reasons:
With the launch of the Sustainable Aviation Fuel (SAF) mandate in 2025, the Department for Transport (DfT) has expanded this model of transparency into aviation. A new SAF-specific report now tracks volumes and fuel types across:
While the first edition remains limited in scope, it is expected to evolve into a robust dataset comparable to the RTFO reports. It will offer deeper visibility into the sector’s progress.
So far in 2025, the numbers paint a challenging picture:
That equates to a SAF blending rate of 1.29%, which is well below the first-year mandate target of 2%.
If consumption trends don’t accelerate, the UK risks missing its compliance goals. With penalties for non-compliance set well above current SAF prices, it’s reasonable to expect blending to pick up as the year progresses.
The comparison with 2024 is even more striking:
Why would a mandate seemingly slow down adoption? The answer lies in policy design.
In 2024, SAF already benefited under the RTFO scheme, encouraging uptake even without binding obligations. Nevertheless, the decline raises questions about whether early mandate structures might be creating unintended headwinds.
Looking ahead, the gap to compliance is significant. If UK jet fuel consumption reaches 12 million tons, then about 240,000 tons (300 million liters) of SAF will be required to meet the 2% target.
With just 75 million liters supplied so far, an additional 225 million liters will need to be blended in the second half of the year.
Zero volumes of Power-to-Liquid SAF have been delivered in 2025. This is not surprising as no commercial PtL facilities are yet online globally.
The UK’s PtL sub-mandate does not begin until 2028. For now, PtL would compete directly with HEFA pathways, which remain far cheaper to produce.
The UK’s SAF transparency initiative is a welcome step in bringing accountability and visibility to aviation decarbonization. But the early data suggests that uptake is lagging behind targets, and that the second half of 2025 will need a sharp increase in SAF blending to avoid costly penalties.
For policymakers, producers, and airlines alike, the message is clear: ambition must now translate into delivery.
Mark your calendar: September 4, 2025 at 9:00 A.M. EDT (1:00 P.M. UTC).
Join Mat Stone, VP of Low Carbon Fuels at ResourceWise, for Biofuels 2025: Foundation for Growth—a live webinar that will cut through the noise and give you a clear view of where the biofuels market is headed.
Stone will unpack the major forces shaping the year ahead, including:
With supply tightening, demand accelerating, and regulations shifting, clarity has never been more critical.
Reserve your seat today and get the insights you need to make confident, strategic decisions for 2026 and beyond.