The uptake of sustainable aviation fuel (SAF) in the UK appears to be falling short of the government’s first annual mandate, according to provisional figures published by the Department for Transport.
Production data covering most of 2025 shows that SAF accounted for just 1.6% of aviation fuel supplied for UK flights, around 20% below the 2% threshold required under the mandate introduced in January. In volume terms, this equates to approximately 160 million litres of SAF used out of around 10 billion litres of jet fuel consumed by early October.
The mandate requires fuel suppliers to meet rising SAF targets within the UK’s aviation fuel mix, a policy the industry says is essential to reducing aviation emissions. The required share of SAF is set to increase sharply to 10% by 2030 and 22% by 2040, including a growing proportion of second-generation fuels considered more sustainable over the long term.
DfT figures show that, to date, all SAF supplied to UK aviation has been produced from recycled cooking oil sourced from Asia, primarily China.
The department cautioned that the figures are provisional due to the time needed for verification, with final data for 2025 not expected until November 2026. A spokesperson said the data did not reflect the full picture, noting that SAF volumes were continuing to rise and that not all suppliers had yet reported their deliveries.
Aircraft using SAF still emit similar levels of carbon dioxide during flight, but the fuel’s overall climate impact is considered lower due to its production process compared with conventional jet fuel. Despite scepticism from some scientists and environmental groups over its scalability, SAF is widely regarded as the most viable option for reducing emissions from commercial aviation, particularly on long-haul routes.
The government continues to support aviation as a driver of economic growth and has approved expansion plans at airports including Gatwick and Luton, while committing to consult the Climate Change Committee on proposals for a third runway at Heathrow.
Speaking at an industry conference in London earlier this month, aviation minister Keir Mather said any Heathrow expansion would need to meet Labour’s four tests, including reducing climate impacts, describing decarbonisation as a “licence for growth”. He said SAF represented the sector’s biggest opportunity and that the government’s SAF bill, currently progressing through the House of Lords, would introduce a revenue-certainty mechanism to guarantee prices, reduce investor risk and boost producer confidence.
Heathrow Airport has introduced incentives to encourage SAF use, including reduced landing charges for airlines using cleaner fuel, and expects to meet its own target of 3% SAF usage over the course of 2025.
Airlines have warned, however, that supplies remain limited outside major hub airports and have questioned whether future mandates can be achieved, particularly as more expensive second-generation and power-to-liquid fuels — which are not yet produced at scale — become mandatory.
The UK remains ahead of many countries in SAF deployment. However, the global aviation industry body International Air Transport Association recently warned that worldwide SAF production growth was stalling, with the fuel accounting for just 0.6% of global jet fuel use in 2025, rising to a projected 0.8% in 2026.
Iata director general Willie Walsh criticised fuel mandates, saying: “If the objective is to increase SAF production to further the decarbonisation of aviation, then they need to learn from failure and work with the airline industry to design incentives that will work.”
Duncan McCourt, chief executive of Sustainable Aviation, said the provisional figures showed the UK was already using significant volumes of SAF. “We remain confident that the mandate will be met and UK aviation will use increasing quantities of SAF in the years to come,” he said.
