The IRS and Treasury have released Notice 2024-49 providing guidance on the clean fuel production tax credit (45Z Credit). Taxpayers aiming to claim this credit must register as clean fuel producers under section 4101 promptly. Early registration is encouraged to receive letters of registration by January 1, 2025, ensuring access to the 45Z Credit. The Notice highlights eligible fuels with emissions rates under 50 kgCO2e per mmBTU, listing various non-aviation fuels like hydrogen, biodiesel, and natural gas, as well as sustainable aviation fuels meeting specific ASTM standards. Additionally, a comprehensive list of feedstocks for clean fuel production is detailed, showcasing a wide range of sources including agricultural residues, biogas, biomass energy crops, CO2 sources, ethanol, and industrial byproducts. The IRS and Treasury stress the importance of a diverse and sustainable approach to fuel production. Taxpayers are advised to stay informed for forthcoming updates and additional guidance on eligibility criteria and emissions rates.