The aviation industry is a major contributor to greenhouse gas emissions, responsible for approximately 2% of global emissions. Sustainable Aviation Fuel (SAF), if produced from renewable or waste-based feedstocks, can reduce greenhouse gas emissions by up to 80% compared to traditional jet fuels. The push towards SAF is not the only response to the growing environmental concerns but is also a result of stringent regulations set by entities such as the EU commission. The aim of the paper is to analyse the SAF supply challenges and the current policy frameworks to incentivise supply of SAF. This analysis reviews the supply from a regulatory and industrial production policy perspective, both against the EU mandates of SAF (Refuel EU) and the proposed use of SAF (e.g., CORSIA/ETS). Further literary analysis explores why a supply gap arises. The role of technology and the need for a standardised method for measuring the life cycles of energy conversions are also important factors for increasing SAF supply. The paper concludes with policy recommendations.