The overall aim of the project, Forestry to jet (F2J), is to produce sustainable aviaion fuel (SAF)from residual forest biomass to meet Swedavia’s target of a fossil free national aviation sector in 2030. Task 2.1 concluded that industrial forest residues (e.g., sawdust, bark, shavings) and harvest residues (i.e., top, brunches, and stumps) can be used as possible feedstock for a continuous production of SAF with Alcohol-to Jet and Sugar-to Jet processes in Sweden. In this context, the objective of this task is to identify potential sustainability issues regarding the selected feedstock as well as to perform a well-to-wing greenhouse gas (GHG) assessment of selected supply chain. The sustainability of bio-jets is strongly dependent on the availability of sustainable feedstock. The availability of forest-based residues for SAF depends on the development of the Swedish forest and forest industry (for instance, demand for timber and pulp and paper) and on the sustainability constraints for residue removals. Swedish forestry is an important source of sustainable material supply. The forest is managed according to the Forestry Act, which gives equal importance to production and environmental goals to obtain a long-term sustainable flow of forest products while preserving ecological processes and biodiversity. The harvested timber is mainly used in saw- and pulp-mills. Residues from saw-mills constitute a potential source of feedstock (2.7 million tons DS) but are used to a large extent. Residues from harvested biomass (tops, branches and stumps) represent an additional source of feedstock for SAF; however, their extraction could lead to environmental challenges such as a reduction in soil and water quality and biodiversity. Currently, about 2.2 million tons DS of harvest residues are used for energy and studies have shown that harvest levels can be further increased to obtain additional 3.3 million tons DS while still being considering sustainable. In this way, the available feedstock would correspond to 1.5 times the total need for the aviation fuel in Sweden (2.3 million tons DS). Sustainable feedstock is determined according to certain “safe thresholds” for harvest residues. The reviewed studies estimated these thresholds so that the extraction of residues does not contribute to forest production reduction, biodiversity loss, acidification, eutrophication, and toxic substances. For a more comprehensive sustainability assessment, other aspects of sustainability, including socio-economic aspects should be considered. It is also relevant to investigate how the demand for SAF affects the availability of feedstock for other competing uses.